17 July 2004
Version 1.9.7

• Licensed version only: Added PNG (Portable Network Graphics), TIFF (Tagged Image File Format) and JPEG file export plugins. These plugins, as well as a replacement plugin for BMP files, all use the FreeImage DLL, a very nicely done toolkit for developers interested in supporting a variety of image formats.
   
• Licensed version only: Added file import plugins for several digital recorders: Tektronix .WFM files, Gould Instrument Systems .DAT files, and Hi-Techniques Win600 .DAT files. These plugins are available to licensed users as an installation option.
   
• Help features have been improved. In particular: Context-sensitive help for all dialog boxes has been brought up to date. Pressing F1 in all but the simplest dialogs brings up the applicable Help topic. Status bar descriptions of menu commands and tool buttons has been brought up to date. The How do I create the example plots? section of the Help file includes additional examples and the existing examples have been improved.
   
• Function parser (used by Y=f(X), etc.) does a better job of syntax checking, particularly with regard to parentheses, and gives more meaningful error messages when an error is found. For example previous versions would accept Y=5(x+4) and produce Y=0. This version balks with "Syntax error: missing operator before open parenthesis."
   
• Modified the Paste code so that it is a bit smarter about interpreting column headings. In previous versions if any heading contained a space or comma then it had to be surrounded by "quotation marks" to be interpreted correctly. This version checks the heading line for tab characters, and if found assumes that column headings are delimited by tabs. So tab-separated column headings may contain spaces and/or commas without being surrounded by quotation marks. See the Help file "How do I create the example plots" for EX02.GRF for an example of this improved feature.
   
• The Number Formats dialog now includes predefined date and time formats (identical to Control Panel's predefined formats) that make selecting an appropriate format a bit easier. Thanks to Aaron Weiner for the suggestion.
   
• Specify extents now works consistently on all 3D plots. In this release, contour lines that fall outside user-specified Z extents are not drawn. This might be useful if you want plots of several slices of your data that all use the same contour coloring scheme without being forced to go to the trouble of redefining colors for each slice.
   
• The new (1.9.6.7) Find volume under surface command has been amended to show volume above and below the reference plane along with the sum and difference of those two volumes. Previous version displayed only the difference.
   
• Generate mesh command now works with Z values on a rectangular grid as well as randomly-spaced points.
   
• Added Label 0 degrees option for polar plots. By default, 0 degrees is not labelled and the maximum radius is labelled.
   
• Improved the appearance of polar plots a bit. Previous versions tended to show small gaps in the circular grid lines if a thick pen was used.
   
• For image file export plugins (e.g. "BMP Picture", "JPEG Picture"), DPlot will now prompt you for the desired image dimensions. Previous versions always used the current dimensions of the plot window. You may leave the width and/or height fields blank to use the window dimensions. Added macro/DDE command SetPluginImageDims to specify these dimensions before using a FileSaveAs command.
   
• The number of available macro shortcut keys has been roughly doubled. Also the macro editor now properly takes into account the presence of the Windows taskbar. Previous versions extended the total height of the screen.
   
• The "Number of symbols used" entry on the Legend dialog may now be set to 0.
   
• Added Distance from command on the Info menu. This allows you to click and drag to find the distance between two points on an XY plot.
   
• Cosmetic changes made to the toolbar. Also provided an XP-like » button to display a dropdown menu for tools that do not fit in the window.
   
• Directory macro command is now more consistent and works correctly with FileSaveAs commands. This command is also no longer restricted to use inside a macro; it may be used in a DPlot_Command call using DPLOTLIB.DLL.
   
• File>Save As... command now skips the File Format dialog and uses the more standard Save dialog in which you can select the file format using the "Save as type" control. All Open and Save dialogs now have a more consistent appearance, are resizable (on Windows 2000 and XP) and display the standard "places" bar on Windows 2000 and XP.
   
• TickInterval macro/DDE command has been amended to allow the angular tick mark interval for polar plots to be specified in degrees rather than the default radians.
   
• Bug fix: Crosshairs tended to leave bits and pieces behind near the edges of document windows.
   
• Bug fix: The Delete triangles command for contour plots gave the perception that DPlot had locked up if you switched to another task and back to DPlot. The command might also have been confusing to users who had hidden DPlot's status bar, since the only instructions appeared there. This version uses a dialog box instead, and restores DPlot correctly if/when you switch tasks.
   
• Bug fix: List Peaks in Box was prone to producing nonsense answers unless you moved the mouse slightly before dragging.
   
• Bug fix: Text boxes that expect floating point numbers for input prevented you from using Ctrl+C, Ctrl+V, and Ctrl+X to copy, paste, and cut, respectively.
   
• Bug fix: The color key for 3D scatter plots was not displayed unless a legend was also displayed, regardless of whether Draw Color Key was checked.
   
• Bug fix: "Symbol sizes in Z units" did not work well for 3D scatter plots.
   
• Bug fix: Y=Poly(Y) command (applies a polynomial transformation to a curve) was broken.
   
• Bug fix: It was possible to crash DPlot by specifying a nonsense angular tick mark interval (e.g. > 360 degrees) for polar plots.
   
• Added DPlot_ZFromXY function to DPLOTLIB. This function allows you to get an interpolated Z value from a surface plot, given X and Y. See ctest2 C demo and/or btest2 VB demo in the DPLOTLIB and/or DPlot Jr distributions.
   

27 June 2004
Version 1.9.6.7

• FileSaveAs macro/DDE command may now use relative paths for the output filename. Paths will always be relative to the path where dplot.exe (or dplotjr.exe) is installed.
   
• Added a command line option to specify which columns to read from a multiple-column ASCII file for XY plots. See "Command line options" in the Help file.
   
• Added Find volume under surface command to the Generate menu for 3D surface plots.
   
• Added methods for retrieving the maximum number of curves and maximum number of points per curve for a given document. This feature is available via the DPlot_Request function of DPLOTLIB, a LinkRequest in Visual Basic, and/or a XTYP_REQUEST DDE transaction in any other language. Request items are "MaxCurves" and "MaxPoints"
   
• Bug fix: A couple of problems with polar plots have been fixed. Using "Specify Extents" to clip the minimum amplitudes on a polar plot usually resulted in one extra spurious line segment. And "Specify Extents" caused all points with negative angles to be clipped.
   
• DPLOTLIB distribution (also included with DPlot Jr) now includes functioning Visual Basic .NET example programs with source code.
   

20 June 2004

20 June 2004
Version 1.9.6.6

• Bug fix: Programmatically it was possible to fool DPlot into attempting to save a metafile and/or copy a metafile to the clipboard with 3D contour plots using shaded color bands. Metafiles are extremely inefficient with these types of plot (think hundreds of megabytes), so that feature has always been disabled for those plots.
   
• Bug fix: One more problem associated with using "Specify Extents" to clip a 3D plot in the Z direction has been fixed. With 3D points on a rectangular grid, if the actual data extents were several orders of magnitude larger than the specified extents then the plot would take a very long time to draw.
   

18 June 2004
Version 1.9.6.5

• Added "(Hidden)" suffixes for hidden curves in most of the "Select a curve" list boxes to help avoid a bit of confusion.
   
• The "Always auto-adjust scale factors on 3D plots" feature now preserves the sign of previous scale factors when the data is amended and/or a link source is updated. In other words if a scale factor was previously negative, the new scale factor will also be negative when it is recalculated after a change to the data.
   
• Added ContourLegendFrequency macro/DDE command.
   
• 2D contour plots drawn with shaded bands (rather than contour lines) will now take the Z extents specified with Extents/Tick Marks/Size into account. Areas outside the specified extents are not drawn.
   
• Line widths, symbol sizes, and other plot attributes are now scaled to give the same appearance regardless of plot size. For example, symbols on a tiled window will have roughly the same relative size as symbols on the same plot in a maximized window. In previous versions this scaling was done inconsistently.
   
• Polar plots may now include negative angles.
   
• Bug fix: Zoom did not work properly on 2D plots of 3D data when negative scale factors were used for X and/or Y. (Negative scale factors can be used to reverse the normal drawing direction. For example, you might set the Y scale factor to -1 if Y represents depth from the surface).
   
• Bug fix: Erasing a curve did not properly shift the "hidden" properties of all curves following the erased curve. For example if curve #2 was hidden and you deleted it, curve #3 (now curve #2) would then be hidden.
   
• Bug fix: The recent change forcing vertical lines to be drawn vertical on 3D plots allowed small roundoff errors at azimuths of 90 and 270 degrees to, in effect, draw a plan view (looking straight down) of the surface regardless of elevation angle.
   
• Bug fix: Specify Columns to Plot dialog omitted the last digit from entries in the last column if the columns were space-separated (rather than comma- or tab-separated). This was a visual problem only; the file was interpreted correctly.
   
• Bug fix: With vertical labels on the Y axis of XY plots, the last label may have been omitted from metafile output, particularly if the plot did not have a title line (which pushed the upper extent of the metafile up).
   
• Bug fix: It was possible to unintentionally select a hidden curve with Edit mode.
   
• Bug fix: If you set the number of contour intervals to 1 on a 2D contour plot with contour lines (rather than shades), using either the Contour Options dialog or the ContourLevels macro/DDE command, no lines were drawn. This was a side effect of a change in version 1.9 that allows you to define contour levels as wrapping from the low to high value by setting the same colors for the low and high ends of the scale.
   
• Bug fix: Standard metafiles (as opposed to enhanced metafiles) of 2D contour line plots copied to the clipboard had random character heights for the axis labels.
   
• Bug fix: The recent change of allowing you to clip a 3D plot in the Z direction by checking "Specify Extents" introduced a problem with drawing grid lines on the plot. Drawing grid lines might have taken an exceptionally long time if the extents were several orders of magnitude smaller than the actual data extents.
   
• XYZSurface and XYZScatter functions of the Excel Add-In have been modified to check the number of used rows in the selection. Previous versions assumed that all rows within the selection contained data, which resulted in sending 65,536 data points to DPlot when you selected a column by clicking on the column heading rather than dragging the cursor over the rows actually populated with data. Those excess data points were all set to 0,0,0. This did not cause any serious problems but of course slowed the entire process down markedly.
   

28 May 2004
Version 1.9.6.3

• Added the ability to change the orientation of numbers along the axes to 45 degrees or vertical. See Options>Number Formats. These settings are applied to most XY plots, 2D views of 3D data, and the amplitude scale of 1D plots. Added corresponding LabelDirection macro/DDE command.
   
• For 3D plots, made a minor change to the 3D projection that forces vertical lines to remain vertical. In previous versions vertical lines were usually drawn at a very small angle from vertical.
   
• User-specified extents on all plots of 3D points are now fully functional. Previous versions ignored the extents for some types of plots.
   
• For logarithmic scales on XY plots you may now specify extents that are not 1, 2, or 5 times a power of 10. The actual extents will be rounded to the nearest number with 2 significant figures that includes the specified extents. Default extents are unchanged and will always be 1, 2, or 5 times a power of 10.
   
• Added Minor tick marks option to the Log Scale Tick Labels menu command, which is a bit more important given the above change.
   
• Symbol frequency setting on the Symbol/Line Styles dialog for XY plots is now an individual setting for each curve, rather than being applied to all curves. Changed the SymbolFrequency macro/DDE command to take this new ability into account.
   
• Negative amplitudes are now allowed on polar plots. If all amplitudes are > 0, DPlot still forces the center of the plot to be at radius = 0, unless you change the extents with the Extents/Tick Marks/Size command.
   
• List Peaks within a Range menu command now displays the same mean, standard deviation, and standard error report given by List Peaks.
   
• Recent addition of specifying a fixed number of decimal places on axis labels is now applied to scientific notation and "powers of 10" number formats as well as the default number format. Both of these number formats now display more significant digits when warranted; previous versions displayed no more than 5 digits.
   
• Added DateFormat and TimeFormat macro/DDE commands to control the display of axis labels using Calendar date, Date and time, or Time number formats.
   
• Default plot extents and tick mark interval for Calendar date and Date and time number formats are more sensible in this version. Previous versions used the same scheme as the default number format when the plot extents were less than 1 day. This very rarely resulted in limits that were whole hours, for example.
   
• Added Select All and Deselect All buttons to the Hide Curves dialog for XY plots.
   
• Plot extents were not recalculated after using the Delete Points in Box menu command.
   
• User-specified tick mark intervals were sometimes saved to DPlot files with an insufficient number of significant figures, particularly when working with a date scale with tick marks at some multiple of hours or minutes rather than days.
   
• Edit mode can now be used to find the distance between two data points on an XY plot. Right-click on a second point on the plot to activate this feature.
   
• Bug fix: An error in updating the settings file dplot.ini upon exit might have caused DPlot, DPlot Jr, and/or DPlot Viewer to crash on older Windows versions, in particular Windows 98 and Windows Me. This error was introduced in version 1.9.5.3.
   
• Bug fix: DPlot crashed under some circumstances when the number of tick mark intervals was set to 1.
   
• Bug fix: ManualScale macro/DDE command did not work properly for 3D scatter plots.
   
• Bug fix: Plot extents set with Extents/Tick Marks/Size for 3D plots were not properly restored from a DPlot file.
   
• Bug fix: Plot extents established with Get Preferences (rather than Extents/Tick Marks/Size) for XY plots were not saved properly to DPlot files.
   
• Bug fix: New Invert X and Invert Y features on the Extents/Tick Marks/Size dialog were saved to DPlot files improperly and caused an error message when the file was reopened.
   
• Bug fix: Operate on X failed to reset a flag indicating whether a curve had a constant spacing along the X axis. So if you used an operation that resulted in a curve having unequal spacing in X (e.g. X=1/X) when it previously did have a constant spacing and you subsequently saved the plot as a DPlot file, DPlot would erroneously save the fictitious spacing and the Y values only, resulting in a nonsense plot when you reopened the file. Thanks to Jim Drake for pointing out the problem.
   
• Amended the plugin interface to allow double-precision data on both input and output arrays. This change will not affect any old plugins, though new plugins that take advantage of this feature will require the current version of DPlot.
   
• Added double-precision versions of DPlot_Plot, DPlot_PlotToRect, DPlot_PlotBitmap, and DPlot_AddData to DPLOTLIB.DLL. Excel Add-In now uses the double-precision version of DPlot_Plot. For many users the most obvious advantage of this change is that date/time entries can now be sent via the Excel Add-In and the precision of the time value will be preserved (down to fractional microseconds). In previous versions date/time entries had a resolution of roughly 3 minutes.
   
• DPlot_Start function in DPLOTLIB.DLL (used by the Excel Add-In and all DPLOTLIB example programs) will now wait up to 5 seconds after successfully launching DPlot for an input idle before returning. This change was necessary for older systems, in particular those running Windows 98, but should not result in any performance penalty for other systems.
   
• Added DPlot_GetVersion function to DPLOTLIB.DLL. This function returns the version number of DPlot (or DPlot Jr) that will be launched by DPlot_Start or any other DPLOTLIB function. The return value of the function indicates whether the full version of DPlot or DPlot Jr will be used.
   

7 May 2004
Version 1.9.5.4

• Improved efficiency of the Delete Thin Triangles command for 3D surface plots. This command will now run much faster with large data sets.
   
• Amended TickInterval and NumTicks menu/DDE commands to include support for the Z axis on 3D plots.
   
• Bug fix: There was a potentially DPlot-crashing bug associated with the recent change of allowing multiple-line title lines and axis labels. This would only occur with metafiles of contour plots, and on all test systems was only a serious problem when running one of the Visual Basic demo programs.
   
• Bug fix: Recalculate extents of XY plots after hiding/unhiding curves was broken by the last revision's changes to the Hide curves command.
   

2 May 2004
Version 1.9.5.3

• You can produce an XY plot from a 3D surface plot that is the intersection of a vertical plane with the 3D surface. See Generate>XY Plot from 3D Surface and/or the corresponding XYZ_to_XY menu/DDE command.
   
• User-specified extents on 3D plots of random 3D points and 3D scatter plots may now be used to view a subset of the data. In previous versions user-specified extents could only be used to "zoom out" on 3D plots. Triangles (or data points on scatter plots) that are not completely inside those extents will not be drawn.
   
• Removed Random spike removal from the Filter command for XY plots and made it a more flexible standalone menu command.
   
• Added Delete Points in Box command to Edit menu. This command allows you to define a box with your mouse cursor, inside of which all visible data points on XY plots will be deleted.
   
• DPlot now does a better job of drawing grid lines on 3D plots of gridded Z values. Previous versions had a few problems with drawing order and roundoff errors, causing gaps in grid lines.
   
• Title lines and axis labels may now use multiple lines. You can add a line break to these entries by embedding a "\n" sequence (the actual characters \n, not a linefeed character) in the string.
   
• Added an option to the Symbol/Line Styles dialog to size symbols in Y units (Z units on 3D scatter plots) rather than 1000th's of inches. If checked, symbols will be resized when you zoom in or out or change the plot extents so that they are proportionately the same size relative to the amplitudes of the plot. Added corresponding SymbolSizeUnits macro/DDE command.
   
• Added Reference lines menu command and corresponding RefLine and DeleteRefLine macro/DDE commands. This allows you to quickly add horizontal or vertical lines to XY plots at a user-specified X or Y value without going to the trouble of creating a new "curve".
   
• Changed Hide all curves but... command on the View menu to Hide curves and made it obvious which curves are already hidden by including checkmarks in the curve list.
   
• On XY plots, you may now have 0 data values and still use a log scale. These points will be ignored, much as points outside the limits using the Amplitude Limits command are ignored: If point N-1 is positive, point N is 0, and point N+1 is positive, you will not get a line segment drawn between point N-1 and N+1.
   
• DPlot, DPlot Jr, and DPlot Viewer are now compressed using ASPack. This results in a moderately smaller download size and a much smaller installed executable (for example, dplot.exe goes from 3255Kb to 660Kb).
   
• Bug fix: When reading ASCII text files containing multiple data sets of x,y,z points for a 3D scatter plot, DPlot crashed if the file was terminated with two or more blank lines.
   
• Bug fix: Choosing to display a plot's filename by use of the Print Caption menu command or ShowCaption macro/DDE command was not properly saved to a DPlot file.
   
• Bug fix: With logarithmic scales, panning a zoomed plot by use of the mouse will pan the nearest number of log cycles. This is by design. However, if you drag less than 1/2 log cycle then the arrow associated with dragging remained on the plot.
   
• Bug fix: Roundoff error might have caused placement of coordinate axes in XY and 1D plots to be off by 1 pixel.
   
• Bug fix: Move up and Move down legend right-click menu items, Reorder Curves menu command and ReorderCurves macro/DDE command might have caused a crash if the plot had more than 16 curves.
   
• Bug fix: GetPreferences macro/DDE command failed to update the plot.
   
• Bug fix: DPlot Jr's File Format dialog used by the Save As... command has been fouled up for several versions, having not kept up with the full version's inclusion of Tab-separated values as an output option.
   
• Bug fix: Previous versions of the Excel Add-In used Integer data types where Long should have been used. The end result was that you were limited to plotting a total of 32767 data points, and you would get an Overflow error in Excel when attempting to plot more points. This has been corrected; you can now plot an arbitrarily large number of points, subject to Excel's limitation of 64K rows.
   
• Amended Excel Add-In to include support for Excel's Percent formatting.
   

12 April 2004
Version 1.9.4.3

• Bah... corrected a bug introduced in the last release. The new Invert X and Invert Y features broke the scaling on multiple Y axes.
   
• You can now use your mouse to pick coordinates in edit mode. In addition, using the mouse to pick X and/or Y values from an XY plot now uses appropriate rounding.
   

10 April 2004
Version 1.9.4.2

• Added support for up to 10 constants in the equation-parsing routines (Y=f(X), etc.)
   
• Added Invert X and Invert Y checkboxes to the Extents/Tick Marks/Size dialog box for XY plots, and added an equivalent InvertAxes menu/DDE command. This feature allows you to invert the normal scaling of the axes without manually specifying the axis extents.
   
• Added AxisType menu/DDE command, which is equivalent to the Grid Lines or Box selections on the Options menu for XY plots.
   
• Edit mode (click on a point to edit the coordinates and/or add a label) is now much more functional for XY plots. Changes are reflected in the plot automatically rather than after you click OK. Also added Insert, Next, and Previous buttons in addition to Delete.
   
• Tick marks with Axes Only or Box Around Plot are now drawn using the same pen width used for grid lines.
   
• Bug fix: Error bar information was not correctly restored from a saved DPlot file unless the data values happened to be evenly spaced in X.
   
• Bug fix: FilePrint(1) menu/DDE command was broken (the "1" is meant to open the Print dialog, where you can select a printer/change printer settings before printing. FilePrint(0) (equivalent to FilePrint()), which prints to the default printer using the current printer settings, worked fine.)
   
• Bug fix: Example DPLOTLIB source code for Absoft FORTRAN resulted in "unresolved external" errors with the linker due to Absoft's default method for passing character string arguments.
   

1 April 2004
Version 1.9.3.8

• Bug fix: Recent change to the List Peaks menu command to display additional information might have caused memory problems seemingly unrelated to this command. In particular, saving a file after using List Peaks might have caused DPlot to crash.
   

30 March 2004
Version 1.9.3.7

• Bug fix: Plots created with [XY()] or [XYXY()] DDE commands and saved as DPlot files were under some circumstances misjudged to have a constant interval in X (which affects how the data is stored in the DPlot file). Thanks to Christophe Boucher for his help in tracking down this problem.
   
• Added DeleteLabel macro/DDE command to delete data point labels created with a TextPointLabel command or Label Points menu command.
   
• List Peaks menu command now displays mean, standard deviation, and standard error values for each curve (along with the minimum and maximum amplitudes).
   
• Fixed a problem with the Excel Add-In that caused columns containing blank cells and plotted with XYYY to produce nonsense plots.
   
• The installation for the Excel Add-In is now a bit more forgiving if it cannot find EXCEL.EXE. This was particularly a problem with users who had Excel installed but did not have Excel set as the default application to use for .xls files.
   

26 March 2004
Version 1.9.3.4

• You may now pan on zoomed XY plots by clicking and dragging in addition to using the arrow keys.
   
• Ten zoom levels are now maintained. Previous versions kept track of only 4.
   
• Bug fix: Recent change of adding support for data point labels on polar plots caused a problem with other plot types - if you used $X in the label to display the X coordinate of a point, the label was actually mod(X,360).
   
• FileSaveAs macro/DDE command did not append a default extension if no extension was supplied. It also failed to update the document caption when saving DPlot files.
   

10 March 2004
Version 1.9.3.2 update

There were several problems with the installation of the DPlot Interface Add-In for Microsoft Excel, namely that it did not work properly on Windows Me or with foreign-language versions of Excel. And it was impossible to install the Add-In on Excel 97 unless macros were enabled. These problems have been corrected in both the evaluation and licensed versions. If you have already installed DPlot 1.9.3.2 and the above applies to you, you can download this much smaller (95Kb) update. Save addinstall.exe to any folder on your hard disk and run it to install the Add-In.

6 March 2004
Version 1.9.3.2

• Added Find Intersections command on the Info menu for XY plots, and corresponding macro/DDE command FindIntersections. This command finds all intersections between 2 curves and optionally adds data points at those intersections and labels those points.
   
• Bug fix: A bug in the last several versions results in incorrect placement of 2D contour plots saved or copied to the Clipboard as metafiles.
   
• Corrected faulty advice in the setup workbook for the Excel Add-In on Excel 97; it is not possible to load the Add-In on Excel 97 or earlier versions without enabling macros.
   
• Made a couple of small adjustments to the way a box is drawn around an XY plot. In previous versions the box was drawn completely inside the extents of the plot, which tended to obscure portions of curves in the corners and may have given the impression of faulty scaling. The problem was particularly noticeable in metafiles. The box is now drawn with the longitudinal axis of each line segment at the respective plot extent.
   

1 March 2004
Version 1.9.3.1

• Added an optional Microsoft Excel Add-In module to the distribution. If you frequently plot data from Excel you should find this feature a big improvement over copying and pasting.
   
• Added Percent number format.
   
• Added the ability to specify the number of decimal places for the default number format (also used in new Percent format).
   
• Bug fix: There were a couple of problems associated with the recent ability to read times (along with dates and currencies) from text files. Fractional seconds were discarded, and DPlot incorrectly decided that column types didn't match from one line to the next if the time values in one line were not in the exact same character position as the time values in the previous line.
   
• Bug fix: Z axis label on 3D plots used the font for the Y axis.
   
• Bug fix: Equation parser caused DPlot to crash in some circumstances when the equation contained extraneous spaces. In particular 'X+ .2' failed, while 'X+.2' or 'X+ 0.2' worked as expected.
   
• Bug fix: Depending on the order of operations, it was possible to save an XY plot with multiple independent Y axes that you've zoomed in on with nonsense zoom window values for the independent Y axis. Reading that file would then cause DPlot to crash.
   
• Bug fix: Recent improvements to the performance of antialiased symbols did not work on Windows 95 or 98.
   
• Bug fix: If a macro resulted in DPlot crashing, the macro facility was left running in an endless loop with a tendency to hog the processor. Though the goal is of course for no macros to cause DPlot to crash, this version of the macro facility will gracefully exit if it finds that DPlot is no longer running.
   

22 February 2004
Version 1.9.3

• Several aspects of working with polar plots were either confusing or did not work properly. Thanks to Ray Delaforce for many of the suggestions:
  • Selecting data points with the mouse in Edit Mode did not work particularly well with polar plots, and not at all for angles in radians rather than degrees.
     
  • Setting the angular tick mark interval on polar plots did not work properly, and it also wasn't clear whether the input should be in degrees or radians.
     
  • Specify extents on the Extents/Tick Marks/Size dialog isn't appropriate for the angular dimension, and in any case produced strange results. These controls are now disabled and hidden, with the extents of course fixed at 0-360 degrees.
     
  • Scan data inappropriately limited you to scanning a (in some cases) small subset of your data.
     
  • You can now zoom in on polar plots.
     
  • In previous versions if you set the radial extents to a value smaller than the maximum radius, the plot was not clipped correctly. This has been fixed (also applies to zoom).
     
• Threw out Dense grid lines menu command in favor of more general settings under the Extents/Tick marks/Size command. In previous versions minor grid lines were either on or off, and if on DPlot decided on the interval. You may now specify the number of minor divisions on both axes. These settings are also applied to tick marks as well as grid lines (previously only grid lines were affected). If you have previously saved a DPlot file with the Dense grid lines option checked, the number of intermediate levels on both the X and Y axes will be set to 4. You can quickly change this setting with the new controls on the Extents/Tick marks/Size dialog.
   
• Added Number Formats command for all 3D plots.
   
• For Powers of 10 number formatting on log scales, if Log Scale Tick Labels is set to Powers of 10 only, then the leading "1x" is omitted.
   
• Relaxed one requirement for bar charts: In previous versions, bar charts required the same constant spacing in X for all data sets. In this version, if only one data set is used then the X values can have an arbitrary spacing. The same requirement is still applied if multiple data sets are used. Also added a bar chart option to draw bars from the given X value to the next X, which is only meaningful in the case of non-constant spacing.
   
• Added ErrorBar, ErrorBarPenWidth, ErrorBarWidth, and LegendShow macro/DDE commands.
   
• Filled areas created with Fill between curves may now include a text entry that is placed in the legend. Amended FillBetween macro/DDE command to account for this new ability.
   
• Added a new General option to recalculate the plot extents after hiding a curve or making a previously hidden curve visible, and ignoring hidden curves in the determination of the extents. By default the plot extents are left unchanged after hiding a curve.
   
• FileSaveAs macro/DDE command now accepts replaceable parameters in the filename. For example, in the "filename" c:\temp\|TITLE1|.dat, |TITLE1| will be replaced with the first title line in the plot. See the description of the FileSaveAs command in the Help file for more information.
   
• Significantly improved the performance of anti-aliased symbols, 10x or more depending on the number of identical symbols on the plot.
   
• Added a Delete button to the Insert Link dialog to help do a bit of housekeeping with the Recently used links list.
   
• Fixed a bug that caused DPlot to crash when reading file type B if the file contained more than one data set and the data arrays were not large enough to accomodate the new data.
   
• Fixed a bug with 3D scatter plots that sometimes caused symbols to be drawn in black rather than the correct color when multiple data sets were plotted.
   
• Fixed a problem with reading multiple-column ASCII files (file type D). In recent versions DPlot balked at blank, quote-delimited columns (two successive quotation marks). It also had trouble parsing quote-delimited dates if one or more spaces were included immediately after the opening quotation mark.
   
• Filled areas created with Fill between curves were not clipped properly in metafiles after zooming in or setting the plot extents such that a portion of the fill area extended outside the plot box.
   
• Corrected a problem with automatically-generated window captions (produced by an FFT, for example). The first FFT would result in a window caption of 'FFT', the second (properly) in 'FFT1', but then the third and all subsequent FFT's would also use 'FFT1'.
   

4 February 2004
Version 1.9.2.8

• Added selections to the Units dialog for tripartite grids to make it quite a bit easier to plot the period of an oscillation (rather than the frequency) on the X axis. This could be accomplished in previous versions only by using user-defined constants. Thanks to Thomas Rockaway for the suggestion.
   
• Fixed a problem with reading multiple-column ASCII files (type D on the Select File Type dialog). In the last few revisions, DPlot balked at blank lines in the header.
   
• Fixed a bug in text output functions. Tabs in notes (or any other text) that contained special control characters (subscript, superscript, etc.) were in effect ignored.
   

30 January 2004
Version 1.9.2.7

• A semi-random problem caused point labels on polar charts to point to the wrong location.
   

29 January 2004
Version 1.9.2.6

• One more problem associated with the switch from single- to double-precision data: Waterfall plots were drawn with a semi-random base plane. Thanks to Gunnar Franke for pointing out the problem.
   
• Selecting Calendar date or Date/time number formatting with values greater than the maximum magnitude of a 32-bit integer (in particular, numbers in the form YYYYMMDDHHMM), caused DPlot to crash. This same action now displays a message box with, in the case of the X axis, a reminder to use the YYYYMMDDHHMM to Serial command if appropriate.
   
• Zooming out with data processing mode turned on sometimes gave incorrect results or caused DPlot to crash.
   
• DPlot files saved with data processing mode on did not properly restore data processing mode when opened from Explorer (as opposed to the Open command within DPlot). Specifically, pressure and acceleration records did not cause DPlot to automatically generate integrated impulse or velocity and displacement records.
   
• DPlot failed to correctly interpret multiple column data files that contained fewer than 20 lines of data and included one of more non-data lines after the data.
   
• Licensed version only: Raw Data file import plugin has been amended to read (if present) a short header containing the number of data sets and the sampling rate for the file. You may now also enter a different default extension for these files; files with this extension will be opened by the plugin when dropped onto DPlot, and you can also associate this extension with DPlot so that double-clicking on a file with this extension in Explorer will open the file with DPlot. Thanks to Chris Rouleau for all of the suggestions.
   

19 January 2004
Version 1.9.2.2

• Bug fix: One more (hopefully the last) leftover problem associated with switching from single- to double-precision data. The Edit Data command contained a few steps that resulted in translating data from double- to single- and back to double-precision, possibly resulting in the loss of significant figures, particularly when dealing with YYYYMMDDHHMM date/time values.
   
• Polar plots: 1) Radial axis labels are drawn along the 0 degree radius. Previously these labels were always drawn along a horizontal line extending to the right from the center of the plot, regardless of whether "0 degrees at top of plot" was checked. 2) Added an option to center radial axis labels on the associated radius. By default these labels are drawn below or to the left of the radius.
   

17 January 2004
Version 1.9.2

• Added Redo command (compliment of Undo) and Redo toolbar button.
   
• Added user preferences for time format on the Number Formats dialog. Previous versions of DPlot always used the time format specified with Windows' Control Panel International (Regional Settings on some versions) applet.
   
• Added a new line style for XY plots.
   
• Added a new Date and Time number format, which differs from Calendar Date only in that the time value will always be displayed (if the time format string isn't blank), while Calendar Date displays the time only under certain circumstances, mostly to do with the granularity of the data.
   
• Added YYYYMMDDHHMM to Serial... command on the Edit menu for XY plots. You may now read date/time groups in the form YYYYMMDDHHMM (for example January 19, 2003 5:25 PM would be input as 200301191725). For DPlot to do anything particularly useful with these numbers requires that they be translated to the Excel 1900 date system, otherwise large gaps would exist between one hour and the next, one month and the next, etc. The YYYYMMDDHHMM to Serial... translates input X values to the Excel 1900 date system, automatically turns on the new Date and Time number format for the X axis, and adjusts the time format setting dependent on the granularity of the input values.
   
• Added Hexadecimal number formatting. You have a choice of 1-, 2-, or 4-byte output, as well as a choice of prefixes.
   
• Minor change to Grain Size Distribution plots now only draws the descriptive labels (Cobbles, Gravel, etc.) that fit within the extents of the plot.
   
• Added an input for the bar width on bar charts/histograms. By default in previous versions, bars butted up against each other (100% width). Default width is now 100% for generated histograms and 75% for all other bar charts, and may be controlled with Options>Linear/Log Scaling>Bar Chart Options.
   
• It is now possible to have bar charts for "curves" consisting of a single point (a single bar) per curve.
   
• Added unit selections for Acceleration plots in Data Processing mode.
   
• Fill Between Curves functionality has been extended to allow you to fill the area between a curve and the X axis, or a curve and a horizontal line with a specified constant Y value. In the latter case, you may also specify different colors for the areas above and below the reference line. For programmers, see the updated description of the FillBetween command. The background of custom fill patterns is now consistent with the pre-defined patterns: the background is transparent.
   
• Axes at 0 tick marks, labels, and line(s) are no longer obscured by curves or fills between curves.
   
• Added an option to turn the radial axis labels on polar plots 90 degrees.
   

Bugs

• Cancel button on Y=f(X,Y1,Y2,...) dialog... didn't cancel.
   
• All 1.9+ versions with 2D contour plots that use "Specify size" had the drawing scale fouled up. This bug was introduced when adding the ability to use negative scale factors.
   
• Fixed a visual bug on the Number Formats dialog that may or may not have shown up on your system, mostly dependent on your screen resolution.
   
• Move/copy curves command did not flag the target plot as changed, or the source plot as changed in the case of a Move (rather than Copy). The result was that you would not be prompted to save these documents when closing them.
   
• Polar plots with angular measurements in degrees that had clockwise angles rather than the default counterclockwise were scaled incorrectly.
   
• Radial axis labels on polar plots sometimes used the incorrect font.
   

• The BMP Picture file export plugin now does a much better job of preserving all colors in the picture. In previous versions, colors set with text formatting commands and colors associated with anti-aliasing symbols (as opposed to colors set explicitly in the color palette) may not have been preserved in the run-length-encoded 256-color bitmap.
   
• The More Curve Fits plugin has been amended to include the equation form y=A*(x+B)^C
   
• The Raw Data file import plugin has been amended to include support for single- and double-precision floating point numbers and multiple data sets, and also has inputs for the X interval between points and an option to read the X interval and number of data sets from a short (8-byte) header in the file.
   

22 December 2003
Version 1.9.1

• Fixed a bug introduced with the addition of "Tab-separated values" to the list of file output formats. File export plugin indices were off by one, such that if you selected "BMP Picture" you'd instead get "JPEG Picture". This bug generally effects licensed users only, as plugins are not distributed with the evaluation version.
   

18 December 2003
Version 1.9.0.9

• Fixed one more problem associated with new capabilities in reading multiple-column text files. If the file contained 20 or more lines of text preceding the data, DPlot would determine that the file contained only text and refuse to process it farther.
   
• Spline interpolation method of Equal Intervals command was fouled up starting with version 1.9
   
• You may now have up to 99 undo levels per document. The previous limit was 8.
   
• Undo files for editing data points with Edit data on 3D surface plots was broken by the addition of 3D scatter plots in v1.9.
   
• Under some circumstance, "undo"ing a change in data did not correctly restore the data, and on Windows XP may have resulted in a crash.
   
• Added the option to save data from any 2D or 3D plot type as tab-separated values, in addition to comma-separated values. As with comma-separated values, this option is only available for XY plots if all curves share the same X values and all curves have the same number of points.
   
• You may now open multiple DPlot files with the File>Open command. Each DPlot file is opened in a new document window. Thanks to Karin Heider for the suggestion.
   
• Last update's feature of using a negative Z scale on 3D plots to reverse the normal drawing direction has been expanded to include X and Y.
   

10 December 2003
Version 1.9.0.8

• Added a simple fix to 3D plots to allow the use of a negative Z scale factor so that the positive Z direction is down in the plot.
   
• Added an option for all 3D data plots to skip 1 or more legend labels. This may be a handy feature if you like using a large number of contour intervals but don't particularly want the legend to dominate the plot.
   
• Equal Intervals command previously forced the start and end points of the new curve to be multiples of the interval. And a couple of roundoff problems sometimes caused the output curve to have 1 less data point than expected.
   
• The elimination of Y=f(Y1,Y2) for the more general Y=f(X,Y1,Y2,...) led to problems with the AddCurves, SubtractCurves, and other macro/DDE commands.
   
• The new capabilities of interpreting CSV and other multi-column files ended up preventing at least one user from reading his standardized file formats, in that the data was preceded by several header lines consisting of a text string followed by several columns of numbers. In previous versions, DPlot would see that the opening text string was not a number, and so decide that the data must start further down in the file. In version 1.9, DPlot still recognizes the opening text string as a non-numeric field, but doesn't disqualify the line from being a data line as a result. If the file contains at least 3 consecutive lines that contain the same number of columns and the same data type in each column (which this user's file format did), then DPlot decided that this must be where the data starts. In this version, DPlot checks for 20 consecutive lines with the same number of columns and the same data type in each column. This change of course isn't foolproof; the addition of more header lines with the same format would cause the 20-line criteria to find a false match. If this ends up being a problem for anyone we'll add an input that asks the user where the data starts rather than trying to determine this automatically.
   
• Several file formats were processed using an older Windows API call that limits filenames to 128 characters.

5 December 2003
Version 1.9.0.5

Argghh! Several bug fixes, most associated with the 1.9 change from single- to double-precision data.

• Smooth command for XY plots produced a botched-up curve.
   
• On some systems under some circumstances, the Contour Options command on the Options menu for 3D surface plots crashed.
   
• FFT crashed if the number of input points was not a power of 2.
   
• New 3D scatter plots did not prevent you from attempting to read a file containing more than 100 data sets (the max) and DPlot crashed if you attempted to do so.
   
• Along with testing 3D scatter plots with a large number of data sets, it was found that a Use last-selected symbol for ALL data sets option would be handy.
   
• Interpolate command caused a crash if a curve used a long legend string (an equation, for example).
   
• BMP export (licensed version only) crashed if the RLE-encoded bitmap required more memory than the uncompressed bitmap.
   

• Added Preserve3DScaleFactor macro/DDE command, which is useful when producing a series of frames that will later be used in an animation, such as the airfoil MPEG referenced on the features page.
   
• Added SetClientRect macro/DDE command. This resizes a document window or the main application window such that the working area has the requested dimensions.
   

2 December 2003
Version 1.9

• 3D Scatter plots.
   
• Internally, all data is now stored using double precision (8 byte) floating point numbers rather than single precision (4 bytes). For the majority of users this change will have little effect. But it will avoid precision problems that previous versions had when plotting large numbers with small (but significant) fractions.
   
• Support for CSV (comma-separated values) files has been greatly improved. Your CSV files may now contain dates, times, date-time pairs, and currencies. In addition, DPlot will automatically ignore columns that aren't interpreted as numbers or any of the other supported types without requiring the use of quotation marks.
   
• Added Delete Thin Triangles command for random 3D data. This command is handy for cleaning up plots generated from truly random data, removing slender triangles from the edge of your surface (also from any interior holes you've created with Delete Triangles). Triangles with interior angles less than 5 degrees are removed if the associated triangle vertex is on a free edge. Thin triangles often do a poor job of mapping a surface. Triangle removal is recursive: if triangle B has an interior angle less than 5 degrees which borders triangle A, and triangle A is removed, then triangle B will also be removed.
   
• Replaced Y=f(Y1,Y2) command with more general Y=f(X,Y1,Y2,...) command. The new command allows you to generate a new curve from an equation that is a function of X and/or one or more of the amplitudes from existing curves. Thanks to Laurent Paris for the suggestion.
   
• For "Month" number formatting, the default tick mark interval on XY plots will be 1 (1 month) if the extents of the corresponding axis are more than 3 or up to 24 (2 years). If the tick mark interval is 1.0, then axis labels will be placed at the center of the tick mark interval rather than centered on the tick marks, as is done with all other number formats.
   
• For "Date" number formatting, several functions (List Peaks, List Peaks in Range, Scan Points) as well as the status bar readout of mouse position show the time of day along with the date.
   
• Added "None" number formatting, which is useful for creating blank graph paper. See the modified "How do I?" Help topic on creating graph paper for a simple macro that creates blank log-log paper.
   
• On 2D contour plots, if you use a custom color palette and set the color for the low and high levels to the same color, then DPlot now considers the contour values to cycle; in other words it considers the low end of the scale to be equivalent to the high end of the scale. In this case, triangles that have all three vertices at either the high or low end of the scale will use the same solid color across the entire face of the triangle. In the case of contour lines, no lines will be drawn on this triangle. Thanks to Bill Frenchu for the suggestion.
   
• Added Polar Plot Options menu command. This replaces the Units command for polar plots and also allows you to specify the orientation of the plot (0 degrees at the top of the plot and/or clockwise angles). It also has a switch to force polar plots to be circular, which saves you from the trouble of specifying a square width and height for the plot. If you want elliptical polar plots, of course you may still have them. Added PolarPlotStyle macro/DDE command to make these same settings.
   
• Point labels (added with Text>Label points menu command) may now be included on polar plots.
   
• Negative angles are now allowed as input for polar plots.
   
• Zoomed views are now saved to and restored from DPlot files. Manually-entered extents are now correctly saved to the values entered. In previous versions if you zoomed in and then saved a file, the extents were saved as the current zoomed view.
   
• Probability scales are no longer forced to be symmetrical. For example, if your data extends from X=0.001 to X=50, then the X axis extents will be 0.001 to 50 rather than 0.001 to 99.999.
   
• DPlot now distinguishes between default input and output folders.
   
• Added "Friedlander's Equation" to the functional forms in the "More Curve Fits" plugin (distributed with the licensed version only). This equation is generally used to fit pressure-time histories from explosive events.
   
• Added a switch to hide/show the legend.
   
• Print margins and orientation are now preserved from one session to the next. (Margin settings may be overridden by margin settings saved in a DPlot file.)
   
• Added fact (factorial), erf (error function), and cdf (cumulative distribution function) to the function parser (used by Y=f(X), et. al.)
   
• Insert Link menu command is now quite a bit more useful, and in general the functionality of linking data from other applications has been improved. The Insert Link dialog now shows recently used links, which may be selected and re-used. There's also a Current links list which shows all of the links for the active document and allows you to unlink data. Most importantly, DPlot now behaves correctly with multiple links in the same document. Thanks to Raymond Delaforce for all of the suggestions.
   
• Added RemoveLink macro/DDE command, which removes the association between the server application and DPlot originally established with an InsertLink macro/DDE command or the Edit>Insert Link menu command.
   
• Starting with this version, if the currently active document window is maximized, then new document windows (created by the File>New command, for example) will also be maximized.
   
• Support for unformatted binary files has been expanded to allow multiple curves in the same file.
   
• "Smoothing window" parameter of the Edit>Smooth command and "Interval" and "Interpolation method" parameters of the Edit>Equal Intervals command are now persistent.
   
• Title lines for all types of plot are now centered horizontally on the plot, not including axis labels or other objects outside the plot box. In previous versions the title lines were centered on the output width, which led to inconsistencies between the display and metafiles.
   
• In previous versions of DPlot, the legend and notes were forced to be on the screen. Unfortunately this led to inconsistent placement between what was seen on the screen and printed or copied to metafiles if, for example, the legend was placed well outside of the plot. In this version the legend and notes are no longer restricted in this way, so that you should get consistent placement on all output devices. This creates a new problem, though: it is now possible to resize a plot such that the legend or notes are completely off the screen and inaccessible. A new menu command (Text>Force legend/notes on screen) has been added to move those items such that they are completely visible on the display. This command is not persistent; it only changes placement at the time you use it.
   

• New symbol types were written incorrectly to preference files.
   
• Symbols used in the legend were clipped if the legend was placed outside the plot.
   
• Corrected bug in macro facility that prevented ForFilesIn loops from working correctly if user had Explorer's "Hide file extensions for known file types" checked.
   
• Equal Intervals command was not enabled properly after creating a single curve unless the curve was created by a method that by definition produced monotonically increasing X values.
   
• Corrected a bug with Text>Label Points command. Selecting a curve with only 1 point caused DPlot to crash.
   
• You were not allowed to draw a lone contour line on 2D contour plots. If you attempted to set the number of intervals to 1 programatically, or if you set the low and high contour levels to be equal, DPlot crashed.
   
• Mouse cursor clipping was fouled up on dual monitor displays after operations that restricted cursor movement (Zoom, List Peaks in Range, et. al.)
   
• Color settings read from a preferences file were assigned to the default color palette (used in new plots), rather than the currently active document.
   
• Removing the first notation (Text>Add/Edit Note) by deleting all of the text in the note (as opposed to clicking the Remove button) caused DPlot to crash.
   

9 September 2003
Version 1.8.3

• Error bar values may now be retrieved from another "curve", so that you may now have unique error bar magnitudes at each data point.
   
• You may now specify how many symbols are used per entry in the legend of XY plots. Previous versions always used 2 symbols. Added an optional parameter to the LegendParams macro/DDE command to reflect this change.
   
• Added Arrowheads menu item to toggle the appearance of arrowheads on the coordinate axes of XY plots when Axes Only is selected.
   
• The user-defined color palette for contour plots may now consist of from 1 to 16 colors (previous versions were limited to 6 colors only). As with previous versions, DPlot interpolates between these colors if there are more contour lines/shades than table entries.
   
• For contour plots with shaded color bands (as opposed to contour lines), DPlot now adds > and/or < symbols to the user-specified high and/or low contour values in the legend if those values are more than 1 contour interval different than the maximum/minimum data extents.
   
• Added "Initially turn symbols off/lines on" to the Options>General menu command. This feature will help avoid frustration for users who frequently plot very large data sets and also, on occasion, create plots with symbols. (By default, DPlot passes symbol and line types on from the first open document to all new documents. So if you work with a plot containing symbols, then create a new plot with several hundred thousand points, you can expect to wait a while as DPlot renders several hundred thousand symbols if this option is unchecked).
   
• Added Erase group menu command for 1D plots.
   
• On the Point Labels dialog, the operation performed by the Ymax and Ymin buttons has been changed such that they will select the maximum or minimum values within the current window (after zooming, for example) rather than the absolute maximum/minimum values. Thanks to Edgar Poth for the suggestion.
   
• File type 'B' (ASCII text file with number of points followed by X,Y pairs) will now accept multiple curves in the same file.
   
• Added toolbar button for List Peaks within a Range.
   
• Removed the "Use arrow keys to pan" message from the status bar when zooming. This message was previously locked in for 5 seconds and was an annoyance for many users.
   
• DPlot Viewer now interprets command line parameters, so you (or your end users) can associate a file type with dplotvu.exe and double-click a file to open it in DPlot Viewer.
   
• Added Bandpass option to Edit>Filter, which allows you to preserve frequencies within a specified range and/or use a low-pass or high-pass filter to reject frequencies above or below a specified limit. Also amended EditFilter macro/DDE command to take into account this capability. Also see the Help topic for the Smooth command for an additional method of low-pass filtering your data.
   

• TextPointLabel command now allows you to rotate labels 90 degrees.
   
• SymbolSize command now allows you to change the size of symbols for all curves with one command, similar to the way the SymbolType, LineType, and LineWidth commands work
   
• Added ContourCustomColors and ContourColorScheme commands, which allow you to specify one of the two predefined color palettes or a custom color palette used to draw contour lines or shades.
   
• Added ContourLabelLines command to allow you to specify whether individual contour lines are labelled, the frequency of the labels, and whether the labels are transparent or opaque and drawn in black or the same color as the contour line.
   
• Changed LineWidth command so that it may be used to set the width of the pen used to draw contour lines.
   
• Changed WindowTile command to accept a parameter that changes the window arrangement from "tall rather than wide" to "wide rather than tall".
   
• Increased the default timeout value in DPLOTLIB functions from 1 second to 10 seconds. The shorter timeout value worked fine for most plots, but was insufficient for large (>10000 points) contour plots of random 3D points.
   
• Line segments drawn as a result of XY or XYXY commands or with the new DPlot_AddData DPLOTLIB function were not repainted properly if the ManualScale command was also used and the DPlot window was covered/uncovered.
   
• Added DPlot_GetBitmapEx. This function is very similar to DPlot_GetBitmap, but also returns plot metric information that enables the calling application to map bitmap pixels to data space. So you can, for example, display the X and Y coordinates corresponding to the current mouse position. The XY plot in the btest2 example program does exactly this.
   
• Added DPlot_GetEnhMetaFile, which retrieves an enhanced metafile of the specified size of an already existing plot. See btest4 (VB demo) and ctest4 (MSVC demo) in the DPLOTLIB distribution.
   
• Added DPlot_SetErrorMethod. The DPLOTLIB DLL now contains much more specific error information, which in general should not be necessary for your released product but may be very helpful during development. DPlot_SetErrorMethod allows you to specify how error messages are displayed: either using OutputDebugString, a system-modal MessageBox, or not at all.
   

• DPlot crashed with formulas used in Y=f(X) and other commands if the formula contained a superfluous leading equal sign, as in "Y=X+5" instead of the correct "X+5".
   
• Version 1.8.2 used several functions from WS2_32.DLL, which is distributed with all Windows versions after Windows 95 Service Pack 2, but not with the original Windows 95. This prevented DPlot from running on some Windows 95 systems. This code has been removed.
   
• Interpolation routine used by the Interpolate menu command incorrectly used linear interpolation on plots with a probability scale on the X axis. Thanks to Michael Duncan for pointing out the problem.
   
• In previous versions it was possible to save a DPlot file that contained a curve with 0 points. This would cause DPlot to crash when the file was re-read. This situation might have occurred as the result of a macro using the SelectCurve command for which the curve index was greater than the number of curves, after which no new points were added to the new curve. Thanks to Karin Heider for pointing out the problem.
   
• DPlot did not properly save notes that consisted of a single character.
   
• ManualScale macro/DDE command did not allow you to specify the Z extents for a 3D plot.
   
• DPlot files saved while in data processing mode may or may not have had data processing mode turned on automatically when the file was re-read.
   
• Filter command for XY plots would crash if you selected the Press notch filter with "reject frequency" set to 0.
   
• DPlot Jr only: Log scale tick labels menu command was missing, and SymbolType documentation was outdated.
   
• Color selections used in 1D plots on a 256-color display were not used correctly. This problem was chiefly apparent with multiple open documents using different color palettes.
   

19 June 2003
Version 1.8.2

• Added Amplitude Limits menu command and corresponding YCutoff DDE/macro command. This allows you to specify the upper and lower limits outside which data points will be ignored. Line segments will not be drawn to or from these points. In this way you can create gaps in your curves. This is particularly handy for plotting data with sign-changing asymptotes, like tan(x).
   
• Added controls to the Titles, Legend/Labels, and Note dialogs to embed color codes within text entries.
   
• DPlot now does a much better job with clipboard metafiles in general and with enhanced metafiles containing embedded formatting codes (subscript, superscript, etc.) in particular. Previous versions of DPlot always copied a standard Windows metafile to the clipboard; conversion to an enhanced metafile was left up to Windows. This left quite a bit to be desired with character placement of subscripts and superscripts. One additional benefit of this change is that enhanced metafiles can in general be stretched or compressed within reason and all of the text entries, including the box around the legend, will be scaled correctly. Scaling was a hit-or-miss proposition with previous versions.
   
• Contour plots now have an option to draw grid lines at the X and Y tick marks, in addition to or instead of the lines bordering the triangular mesh or rectangular grid cells.
   
• For developers, the ManualScale command now behaves with XYXY in much the same way as it does with XY: If an incoming X value exceeds the upper limit of X, DPlot pans to the right by 1/2 of the X extents.
   
• Font colors are saved to DPlot files. In all previous versions colors were initialized to black, regardless of your previous color selections.
   
• Bug fixes:
  • Legend on both 2D and 3D contour plots was printed in the wrong location, depending on what the print margins were set to.
     
  • Previous change to Smooth command allowing you to smooth a subset of the data introduced a new bug that caused this command to crash in some circumstances. Thanks to Jean-Louis Oneto for pointing out the problem.
     
  • Clicking the close (X) button (rather than the Cancel button) on any of the Edit Data dialogs would cause DPlot to crash on some versions of Windows.
     
  • Copy/Move Curves was prone to produce needless "insufficient memory" errors if you attempted to copy a large number of data points (say, 1 million) to a document that had a large maximum number of curves, e.g. 100. Reallocation is handled better now, only allocating memory for however many curves are actually needed rather than preserving the previous maximum.
     

1 June 2003
Version 1.8.1.2

• Added a workaround to make box and whisker plots be recreated correctly in metafiles pasted from the Clipboard in Microsoft Office 2000 products. In previous versions, if most or all of the plot options were enabled (outliers, extremes, etc.) then a glitch in Office products caused them to lose track of the current drawing pen, resulting in (usually) whiskers not being drawn.
   
• Bug fixes:
  • DPlot's formatting codes for subscripts, superscripts, Greek characters, etc., are now supported on axis labels of 3D plots. Thanks to John Spalding for the prod to get this working.
     
  • Also related to 3D plots, Generate Mesh command did not properly transfer axis labels from the source plot to the generated plot.
     
  • The triangulation routine used for random 3D points attempts to create non-slender triangles, which is as it should be. But in previous versions of DPlot, units (and therefore data extents) were ignored. This had the unfortunate effect of creating a plot consisting of very slender triangles if the X extents differed significantly from the Y extents. In this version, DPlot temporarily squares up the X and Y values by scaling one or the other of those coordinates, resulting in a much better contour plot for data with differing X and Y units. Hats off to Ralph Baird for pointing out the problem.
     
  • If a non-zero pen width was used for the coordinate axes, symbols lying exactly at an axis extent were not drawn. This version takes the axis pen width into account and properly draws those symbols.
     
  • If manually-entered extents were used to reverse the direction of the Y axis, the values for a second dependent Y axis were drawn incorrectly if Box Around Curves (rather than Grid lines) was used.
     
  • Box and whisker plots copied to the Clipboard as metafiles were not clipped properly if you used Extents/Tick Marks/Size to view less than the total extents of the data. Thanks to Colin Wagoner for pointing out the problem.
     

29 May 2003
Version 1.8.1

• Added 18 new symbol styles, for a current total of 38. Also added an option to use antialiasing techniques for drawing symbols on 16-, 24-, and 32-bpp displays. See Options>General.
   
• Added the ability to pan left, right, up and down on zoomed XY plots. No buttons required, just use your keyboard arrow keys. This has been suggested many times in the past; thanks to Ed Quick for the prod to finally put this into action.
   
• Added several new menu commands to specify the frequency of labels on logarithmic scales. See Options>Log Scale Tick Labels.
   
• In response to several inquiries along the lines of "How do I change the order of the legend?" we've added two new commands to the right-click menu for the legend: Move up and Move down and a new Reorder Curves command on the View menu. Reorder Curves replaces the less useful Bring to Front and Send to Back commands.
   
• For new users, the How do I? section of the Help file now includes step-by-step instructions for creating many of the example plots distributed with DPlot.
   
• Added Median of All Curves command to the Generate menu, and corresponding Medians() macro/DDE command. This command produces a new curve consisting of the median amplitudes of all existing curves. Thanks to Mason Guy for the suggestion.
   
• Added Swap X,Y command to the Edit menu for 3D plots. This option might be useful if, for example, your 3D input files are ordered latitude, longitude, elevation (rather than longitude, latitude, elevation). Thanks to Risto Salo for the suggestion.
   
• Multiple column files containing X-Y data may now include a data row ID character string, specified at the time the file is opened. Thanks to Nick Cooper for the suggestion.
   
• For unequally spaced points, the Differentiate command now uses a central difference method for calculating slope. Previous versions used an inverse trapezoidal rule. While technically correct, this generally resulted in roundoff errors being propogated forward and giving increasingly bad results with increasing X. Thanks to Sukhdeo Karade for the suggestion.
   
• For box-and-whisker plots and dot graphs, you may now specify the color of the line used to depict the grand mean or median. Changed Stat_GrandMean macro/DDE command to include an optional color parameter.
   
• Y=f(X) command now allows you to enter a from X value smaller than to X.
   
• Changed LineType and SymbolType macro/DDE commands so that you can easily set the line and symbol types for all curves to the same value with one command.
   
• Added ColumnsAre macro/DDE command to tell DPlot that multiple column files subsequently opened with FileOpen or ForFilesIn commands should be interpeted as alternating columns of X and Y rather than the default one X column with multiple Y columns.
   
• Bug fixes:
  • Fixed the default extents for box-and-whisker plots such that whiskers (if drawn) will not be clipped.
     
  • Macro/DDE command names that included an underscore character were not processed properly by the macro facility.
     
  • Last version's fix to small roundoff problems did not work properly for negative values used for user-defined extents on X-Y plots.
     
  • DivideCurves macro command did not work. Thanks to Michael Sears for pointing out the problem.
     
  • Zooming on XY plots with multiple Y scales sometimes produced illogical extents on the second Y axis.
     
  • Labels for multiple Y axes with a probability scale on X and linear scale on Y were incorrect. Thanks to Kirt Harle for pointing out the problem.
     
  • Several problems with color mapping on 256-color displays have been corrected. These problems were a byproduct of a fairly recent change allowing unique color palettes for each open document.
     
• Licensed version only:
  • Added inverse polynomial (y=1/(A+Bx+Cx^2+...)) to the curve fitting plugin.
     
  • Added file import plugin to read raw data files consisting of 8-, 16-, or 32-bit signed or unsigned data, with either Intel or Motorola byte order.
     

26 April 2003
Version 1.8.0.2

• Previous versions did not draw symbols at data points lying on the X or Y axis extents.
   
• Bug fix: The equation parser (used by Y=f(X), etc.) crashed if your equation contained an operator (+,-,*,/,^) followed by a negative number not enclosed by parentheses. The parser also failed to trap the error of raising zero to a negative power.
   
• Bug fix: Probability scales on the X axis bombed for X values outside the range 0.01-99.99. In this version the X axis is treated identically to the Y axis: values outside the range 0.001-99.999 are clipped.
   
• Bug fix: Small roundoff errors when using user-defined extents might have caused incorrect extents to be used.
   
• Added Combine Curves command to the Edit menu. This allows you to append the data values from one curve to another curve. Added corresponding CombineCurves macro/DDE command
   

13 March 2003
Version 1.8.0.1

• Bug fix: The equation parser (used by Y=f(X), etc.) crashed if your equation included an operator followed by a number with a leading decimal point. For example, Y=X*.25 crashed, while Y=X*0.25 worked.
   
• Bug fix: Equation parser did not correctly interpret numbers using scientific notation (i.e. 1.5E+3). In most cases this resulted in the number being interpreted as 0.
   

10 March 2003
Version 1.8

• Point label placement on XY plots is now more consistent and less annoying. Previous versions were prone to shift labels around in an effort to ensure good arrow placement. In this version, labels stay where you put them and the arrow anchor point will shift to one of the 4 sides of the label as needed. Added a setting to draw labels turned 90 degrees. And last, you may now include up to 50 labels in a single plot (previous limit was 20).
   
• Both major and minor grid lines on XY plots may now be drawn with a line style other than solid lines. Also added missing support for Dense Grid Lines setting to polar plots.
   
• Added Powers of 10 number formatting. This is a nice enhancement over scientific notation (e.g. 1.45E+3)
   
• Smooth command on the Edit menu has been modified to allow you to operate only on points between specified limits. The corresponding EditSmooth macro command has likewise been modified. Thanks to Dr. Thierry Picornell for the suggestion.
   
• Bug fix: Corrected placement of Y and Z axis labels on triangle plots for output to metafiles.
   
• Bug fix: Depending on the version of Windows in use, DPlot would either crash or produce a bogus error message when reading .CSV files containing X,Y,Z points (file type K) if the file contained one or more extra blank lines at the end of the file.
   
• View>Playback command now has the ability to view an AVI file along with your data, played frame-by-frame in sync with your data at the speed you specify. The majority of users who read this will scratch their heads and wonder what the point of this is. If, on the other hand, you spend hour after hour analyzing video footage and megabyte upon megabyte of data recorder output from high-speed events (things that go BOOM, for example), you'll most likely find this addition to be very, very,.... very cool.
   
• Added SymbolFrequency macro/DDE command for XY plots. Thanks to David McDaniel for pointing out the oversight.
   
• Changed both the plugin and DDE interfaces to allow you to plot and/or operate on up to 100 curves/plot, and work with legend entries of up to 80 characters. Previous limits matched those of older versions of DPlot (20 curves/plot, 40 character legend entries). This change will not break existing plugins or applications sending data to DPlot.

DPlot Jr/DPLOTLIB.DLL

DPlot Jr distribution now includes DPLOTLIB.DLL and several new example programs using DPLOTLIB.

Additions to DPLOTLIB:

• DPlot_PlotToRect is similar to DPlot_Plot, but starts up DPlot (or DPlot Jr) in a hidden state and draws the plot to a caller-specified rectangle in a specified window. The picture is not preserved in any way, so that if it is covered by another window it is then basically gone for good. You may, however, be able to think of several applications where this behavior might be useful. To keep the picture, you need....
   
• DPlot_PlotBitmap is very nearly identical to DPlot_PlotToRect, but rather than drawing the plot returns an HBITMAP handle to a bitmap representation of the plot. It is the calling application's responsibility to then draw the bitmap and delete it when it is no longer needed. Both DPlot_PlotToRect and DPlot_PlotBitmap clean up after themselves: DPlot will be closed before the function returns, unless it was already running. To speed things up a bit and avoid starting DPlot every time you want a new picture, use DPlot_Start (see below)
   
• DPlot_GetBitmap does not draw anything; it retrieves an HBITMAP handle to a bitmap of a specified plot, usually, but not necessarily, a plot generated by the calling application. As with DPlot_PlotBitmap, it is the calling application's responsibility to draw the bitmap and delete it when it is no longer needed.
   
• DPlot_Start starts up DPlot (or DPlot Jr) with an option to hide it from the user. This function will also tell you whether DPlot was already running when called, so that you don't annoy the user by closing DPlot when the user didn't want it closed.
   
• DPlot_Stop closes DPlot if it is hidden or if no open document windows contain a plot. This function should only be called if DPlot_Start was used to open DPlot and the program was not already running.
   

11 February 2003
Version 1.7.9.2

• Bug fix: (Whoops) New More Curve Fits plugin released yesterday retained debugging code that would cause the plugin to crash on all systems other than the author's. Very sorry for the inconvenience.
   
• Bug fix: Baseline Shift plugin did not properly catch the case of the detected arrival time occurring at the first data point in the input. This caused a divide by zero error and... another crash.
   
• Bug fix: Notes did not work properly with metafiles copied to the Clipboard on Windows 2000 and XP. One other strange aspect of metafiles that has also been fixed: Office 2000 products displayed black grid lines unless the grid line width was greater than 1 pixel, though the Windows ClipBook Viewer displayed the correct color.
   

10 February 2003
Version 1.7.9.1

• Bug fix: Function parser used by Y=f(X) and other commands did not work properly with numbers containing trailing decimal points if that number was followed by an operator. So even though "10+x", "10.0+x", and "10.+x" are functionally equivalent, the first two forms worked as expected but the last form would cause a crash.
   
• Bug fix: File Append with DPlot files did not work properly unless the maximum array sizes were already set to values large enough to accommodate the new file.
   
• Bug fix: Not so much a bug but a design flaw, when opening a file if the number of points in the file exceeded the current maximum number of points, DPlot would attempt to reallocate the arrays using the required number of points and the current maximum number of curves. So if, for example, you had arrays allocated for a maximum of 100 curves and attempted to open a file containing 1 million points, DPlot would attempt to allocate arrays for 100 million points.
   
• Bar charts:
  • Formatting options have been expanded to include percentage labels instead of or in addition to amplitude labels.
  • Labels may now be placed above bars. Previous version always drew labels just inside the top of the bar, and bars shorter than the label text did not include the label.
  • Bar chart options have been added to the input dialog for Generate>Histogram so that you can generate a bar chart with the options you want the first time, rather than being required to edit the options of the new chart.
  • Last accepted bar chart options are preserved from session to session and are now the default options for any new bar charts.
  • Bar charts may now include error bars. For best results turn off all labels and use side-by-side (rather than stacked) bars with multiple data sets.
  • Histograms will copy both the 1st and 2nd title line (if one exists) from the source plot. Previous versions copied the 1st title line only.
  
   
• Curvefit plugin (licensed version only):
  • Added one new equation form: (Y=A+B*exp(C*X)+D*exp(E*x).
  • Improved determination of default initial coefficients for several equation forms.
  • Added a max iterations entry that might be useful for the exponential forms that tend to converge slowly.
  • The plugin now takes a bit of preemptive action in forcing coefficients to legal values in the case of the exponential forms. This change allows a poor initial fit to find a better solution without blowing up with an overflow error.
  
   

6 February 2003
Version 1.7.9

• Added Edit Mode tool which allows you to point/click/edit data points for XY plots and 2D plots of 3D data. For XY plots you may also optionally label the point using this tool.
   
• For the licensed version only, improved initial estimates for the coefficients in an exponential curve fit. Previous versions worked well for more-or-less noiseless input, but not well at all with a lot of scatter.
   
• Added the ability to import macros from disk. This is useful if you are running DPlot on multiple systems and/or want to be able to share macros with others with a minimum of fuss. Imported macros will be copied to the /MACROS folder below DPlot.
   
• Tick mark intervals for calendar dates (set with the Number Formats command) are now much more sensible, falling at the 1st and/or the 15th of every month depending on the extents of the data. Previous versions placed tick marks at equal intervals (equal number of days).
   
• Custom colors used in contour plots may now be saved and re-opened on the Contour Plot Colors dialog. Also added color picker controls for each of the six colors. Previous versions required you to enter explicit r,g,b values for each color. Thanks to Ukuleles by Kawika's David Hurd for the suggestion.
   
• For 3D data, added a preview of the contour values to the Contour Plot Options dialog that takes some of the guesswork out of selecting an appropriate number of intervals, lower limit and/or upper limit.
   
• DPlot now does a much better job of picking an initial number of contour intervals. Default contour values will now be some multiple of 1, 1.5, 2, 2.5, 4, or 5 times a power of 10.
   
• Whoop! Added ability to label contour lines on the plot, rather than restricting you to using the legend. You control whether the labels are transparent or opaque, same color as the corresponding line or black, and the frequency of the labels. This feature will no doubt be tweaked a bit; if you try it and have a suggestion, of course let us know.
   
• Added OperateX, OperateY, and OperateZ macro commands, corresponding to the new menu commands that allow you to manipulate plot coordinates with an equation.
   
• Bug fix: If you either zoomed in or forced the extents of a 2D plot of contour lines, saved metafiles did not properly draw the contour lines.
   
• You may now control the line weight of contour lines on 2D contour plots. Previous versions fixed the line weight at 1 pixel for display monitors and bitmaps and 0.01 inches for printed output. Thanks to Herb Sorensen for the suggestion.
   
• Add a Constant to |X,Y,Z| and Multiply |X,Y,Z| commands have been eliminated in favor of a more generic Operate on |X,Y,Z| command that allows you to manipulate plot coordinates with an equation that is a function of X or Y for XY plots or X,Y, and/or Z for 3D plots. Thanks to Dimitris Evangelinos of the Aristotle University of Thessaloniki for this and the following suggestion.
   
• Multiple column input files (type D on the Select File Type dialog) may now contain non-numeric columns within the data, as long as those columns are "surrounded by quotation marks". DPlot will ignore non-numeric columns, other than to display them on the Specify Columns to Plot dialog.
   
• Function parsing routine now accepts log10 in addition to logh for base 10 logarithms.
   
• Bug fix: Saved metafiles (both enhanced and standard Windows) for 2D contour plots did not use the correct font for numbers along the X and Y axes, and included much more white space than necessary.
   
• Bug fix: Function parser used in Y=f(X), X=f(T), Y=g(T), and Z=f(X,Y) commands did not properly trap raising a negative number to a non-integer power. Attempting to perform this operation resulted in a crash.
   
• Bug fix: In previous versions if you turned on Data processing mode when more than two curves were present, then later used Undo to turn data processing mode off, DPlot crashed.
   
• Bug fix: Negative values on stacked bar charts were not drawn as most would expect, which is to say they were inconsistent with how Microsoft Excel draws them. New bar labelling feature did not work at all with negative values.
   

17 January 2003
Version 1.7.8

• Added Playback command to the View menu, which allows you to animate one or more XY plots.
   
• Bug fix: DPlot now traps underflow errors on input and truncates offending numbers to 0. In previous versions, it was possible to read a file or paste data from the clipboard that contained values with magnitudes less than 1.17549E-38 (roughly the limit for single precision floating point numbers). This behavior could eventually cause a crash, usually when writing a file to disk. Thanks to James Drake for pointing out the problem.
   
• Bug fix: Math errors (divide by zero, for example) in the function parsing routines used by Y=f(X), etc. caused a crash on Windows 2000, regardless of whether Prevent divide by zero was checked.
   
• Bug fix: The last several versions failed to detect any of the data recorder file formats when a file of that format was dropped onto DPlot's window. This version should successfully identify any of the supported data recorder file formats without user intervention.
   
• Moved bar chart formatting options from the main menu to a separate dialog and added Bar amplitude labels option. If checked, labels showing the height of each bar are drawn near the top of the bar. BarChartStyle macro command has been expanded to include flags for stacked bars and bar labels.
   
• Added GenerateMesh macro command to produce a rectangular grid of 3D points from a triangular grid of random 3D points.
   
• Several commands on the Edit menu for XY plots now allow you to select multiple curves to operate on. Previous versions allowed you to operate on all curves or one curve only. Thanks to Susan Blouin for the suggestion.
   
• Added RunPlugin macro command, which allows you to run any of the Generate menu's plugin modules from within a macro or from another program.
   
• Bug fix: Custom line drawing routine used for XY plots with patterned line styles did not properly handle (again) densely-spaced data points. Hopefully this version represents the final fix to this problem.
   
• Bug fix: Label Points command for XY plots improperly placed labels for the first data point in a curve.
   
• Bug fix: Macro editor improperly overwrote previously saved macro files with new macros if the first 5 letters of the macro names were identical.
   
• Added Delete Triangles command to the Edit menu for randomly-spaced 3D points. This command allows you to select and delete multiple triangles in one pass, an improvement over the right-click context menu command described below.
   
• Added a planar interpolation method to the Generate Mesh command for randomly-spaced 3D points. Although the bivariate interpolation scheme used in this and older versions works very well with smooth surfaces, it is a very poor interpolator for meshes that have sudden changes in Z. The planar interpolation method simply maps each generated point to the plane of the triangle that bounds the X,Y coordinates. The resulting surface will not be as smooth as one produced with the bivariate method, but it will correctly handle sudden changes in Z.
   
• Added Number triangles command to the Edit menu for randomly-spaced 3D points. This feature is useful when deleting triangles from the mesh. Why delete triangles? DPlot will always triangulate a convex mesh from your input 3D points. Although (given the limited information in the input) this is "correct", it may not always be what you want. You can now delete triangles from the mesh by right-clicking on triangle N and selecting Delete Triangle (N), where N is the triangle number.
   
• Changed the drawing order for 2D contour line plots. In previous versions grid lines were always drawn last, possibly obscuring the contour lines.
   
• Relaxed syntax checks when reading DPlot files. In previous versions if a DPlot file contained new settings not supported by older DPlot versions, an older version of DPlot would balk and refuse to produce a plot. This version will instead display an error message and suggest that you update DPlot. The key difference is that the plot will now be displayed.
   
• Bug fix: For 2D contour plots of random 3D points, if a contour line passed exactly through the vertex of a triangle then in many cases the contour line segment for that triangle was not drawn.
   
• You may now specify the color of grid lines. Default grid line color is light gray (r,g,b=192,192,192) for XY and 1D plots, black for 3D plots. You can change grid line color programmatically using a new setting for the [Color()] command.
   
• Bug fix: The last several versions of DPlot have been distributed with a version of FPARSER.DLL (used to generate data by formula) that did not include exp, sinh, or cosh. These functions have been re-added.
   
• Bug fix: It was possible to confuse DPlot's "Multiple Print" feature into adding a non-existent blank document to the list of documents to be printed. This generally led to a crash if you then attempted to print.
   
• Added View>Crosshair cursor menu command and corresponding toolbar button. This feature is useful for visually comparing the amplitude of a point to a reference value. Thanks to Peter Riggs for the suggestion.
   

• Added Baseline Shift plugin module. This plugin differs from the Edit menu command of the same name in that it automatically detects the arrival time in the record, rather than requiring the user to input the value. Whether this operation is successful or not of course depends on how noisy the input record is. For more information see the description at the bottom of the Features page.
   
• Bug fix: Error checking in the More curve fits plugin has been improved dramatically. Previous versions had a bad tendency to crash (and take DPlot with it) if math errors occurred (overflow, underflow, division by zero, etc.). Some equation forms (particularly the power series) tended to produce those errors if care wasn't taken in the selection of the initial coefficient values.
   

11 December 2002
Version 1.7.6.1

7 December 2002
Version 1.7.6

• Legend character strings may now be up to 80 characters long. Previous limit was 40.
   
• Bug fix: For XY plots, the frame surrounding the legend was improperly sized too wide if the legend used any of the hidden formatting symbols.
   
• Bug fix: Symbol/Line Styles dialog for XY plots used the wrong color palette to draw example lines and symbols. This was a side-effect of a recent change giving each document a separate color palette rather than using a global palette.
   
• Text notations may now be included on 3D plots.
   
• The Select Columns to Plot feature for multi-column ASCII files now allows you to interpret the file as alternating X,Y values rather than the default interpretation of a single X column with one or more Y columns.
   
• Added Stacked Bars menu command. This feature controls whether bars in bar charts for multiple data sets are drawn side-by-side or stacked from bottom to top.
   
• The behavior of Text>Date has been changed so that the date is updated only when this feature is turned on and/or when the plot is saved as a DPlot file.
   
• Added Day of the Week (1=Sun, 2=Mon, etc.) and Month (1=Jan, 2=Feb, etc.) formatting to Options>Number Formats.
   
• Bug fix: File>Append with a DPlot file containing manual extent specification may in some circumstances have caused a crash.
   

24 November 2002
DPLOTLIB.DLL

13 November 2002
Version 1.7.5

• Added waterfall plots of gridded 3D data. The color options for these plots are currently non-existent. Have a suggestion? Let us know.
   
• Added List Peaks within Range menu command. This is identical to List Peak Values, but first allows you to specify a range in X with the mouse.
   
• Added Clear all button to Specify Columns to Plot dialog, which is handy for files with a large number of data columns.
   
• Bug fix: Attempting to add 2 or more notes at once (Text>Add/Edit Note) caused DPlot to crash.
   
• Bug fix: For XY plots, in some circumstances DPlot's custom line-drawing routine would enter an endless loop. The custom line-drawing routine is used for line styles other than solid, all metafile output, and if the "UseDPlotClipping" flag in the [Debugging] section of dplot.ini is set to 1.
   
• Bug fix: DPlot balked at opening the 32nd document, claiming that too many documents were already open (32 is the limit).
   
• Bug fix: DPlot did not previously save "Use thousand separator" selection to a DPlot file. This behavior was actually by design, but was confusing.
   

4 November 2002
DPLOTLIB.DLL

26 October 2002
Version 1.7.4.1

25 October 2002
Version 1.7.4

• Added two new functions to DPLOTLIB.DLL: DPlot_Command allows you to send one or more command strings to DPlot. DPlot_Request provides a facility for retrieving information from DPlot.
   
• Color selections for XY plots are now saved to DPlot files. Also, the global color palette is no longer used, other than to initialize colors for new documents. So you may now have a different color palette for every open document.
   
• Streamlined color selection process for XY plots. DPlot now uses a single color palette for all output devices. (Previous versions used one palette for printers, another palette for all other devices). A single menu item has been added to force printed output to be rendered in black and white. If this menu item isn't selected, B&W printers will simulate the selected color palette with gray shades.
   
• A recent addition that removed duplicate X,Y values from random 3D points was horribly inefficient on large data sets. Performance with more than 10000 or so points is quite a bit better in this version.
   
• FileType macro command will now accept a file import plugin description in place of a file type code. So if you want, for example, to open all of the WAV audio files in c:\windows (and you have the WAV Audio plugin distributed with the licensed version), you can:
   
  Directory("c:\windows")
  FileType("WAV Audio")
  ForFilesIn("*.wav")
  NextFile
   
• Similarly, FileSaveAs macro command will now accept a file export plugin description in place of a file type code. So if you want, for example, to save JPEG images of all of the DPlot files in a folder (and you've installed the JPEG export plugin), you could use this macro:
   
  ForFilesIn("*.grf")
     DocMaximize()
     FileSaveAs("JPEG Picture",".jpg")
     FileClose()
  NextFile
   
• For programmers, added optional parameters to the ManualScale command that allow you to specify the extents of a second, independent Y axis.
   
• All dialog boxes that allow you to pick a curve from a list composed of curve legends now display those legends complete with the various text formatting options (subscripts, superscripts, symbols, etc.). Previous versions removed those formatting codes from the lists, with the result that the legends might have been a bit more difficult to read.
   
• 3D plots of random points have been improved a bit. Previous versions included roundoff errors with drawing grid lines.
   
• Added an option to draw solid white polygons for the sides of 3D contour plots, extending from the edges of the surface to the XY plane (see example here.) These polygons obscure the underside of the surface, and in many cases add clarity to the plot.
   
• Bug fix: Version 1.7.3 came close to solving problems with using patterned line styles with a large number of points, but didn't quite get there.
   
• Bug fix: Multiple X axes settings (set with Options>Multiple Axes) were not saved to DPlot files properly. Also related to multiple X axes: secondary X axis label was not placed correctly in metafile output.
   

16 October 2002
DPLOTLIB.DLL

10 October 2002
DPLOTLIB.DLL

21 September 2002
Version 1.7.3

• You may now have 32 open documents (plots). Previous limit was 8.
   
• Label Points menu command now allows you to automatically jump to a point with a specified X value, rather than using the horizontal scrollbar to scan through the points. This is particularly useful with large data sets. Similarly, added options for placing the label at the point with the maximum or minimum Y value.
   
• For programmers, added an options parameter to the TextPointLabel command that allows you to specify points as described above. Options also allows you to specify the X and Y coordinates for the label text as relative offsets from the labelled point, rather than absolute position.
   
• If you previously used PI fractions or PI multiples number formatting on either the X or Y axes, then the display of X, Y coordinates on both the Scan Points and Point Labels dialogs was a bit ugly (PI symbol was displayed as {\sp}). This has been corrected.
   
• Fill Between Curves feature did not work with polar plots. This was intentional and due to a limitation in older versions that no longer exists. It now works as expected.
   
• A bit of fine-tuning on axes adjustments with logarithmic scales and multiple independent Y axes. Previous release was correct, but tended to either clip one or more curves or have axis extents larger than necessary.
   
• Corrected a couple of problems associated with plotting a very large number of points. If the plot contained enough points such that consecutive data points were scaled to the same location, the line drawing routine used for metafiles would skip over that point. This problem did not effect output to the display, printers, or bitmaps. For all output devices, line styles other than solid would be rendered as solid under the same circumstances (multiple data points scaled to the same physical location).
   
• Changed the definition of "dotted" lines to 25% filled-in from the previous 50%. Using the old definition with line widths greater than 1 dot resulted in solid lines. If this change presents a problem for anybody, of course let us know and we'll likely add a new line style.
   
• Bug fix: Equal Intervals command caused DPlot to crash if the selected curve consisted of only 1 data point or if the X values for the first and last point were equal. Both of these situations now display an error message rather than bombing.
   
• The equation parsing menu commands (Y=f(X), X=f(T),Y=g(T), and Z=f(X,Y)) now allow you to specify angles in degrees or radians. Previously you were required to use radians. So you can now plot, for example, Y=sin(X) from X=0 to 360 degrees rather than Y=sin(PI*X) from X=0 to 2.
   
• File type D (multiple columns) used an arbitrary line length of 224 characters to read multi-column files. Depending on the number of significant figures used in the file and/or the width of each column, this might have resulted in DPlot reading fewer columns than the file contained. The maximum line length has been increased to 1024 characters. This will most likely be changed to an unlimited length in a future version.
   
• Bug fix: If an additional curve was generated/created/read from a file while zoomed in, and you then used the Multiple axes command to associate the new curve with a second Y axis, DPlot crashed. This release solves the problem by zooming out when the Multiple axes command is used in this way.

30 August 2002
Version 1.7.2

• Fractions number formatting now draws fractions using smaller, shifted characters and generally has a much better appearance.
   
• Added an option to control print orientation (landscape or portrait) to the FilePageSetup DDE command.
   
• Added CurveLabel and Stat_LimitsAsCL DDE commands.
   
• Curve labels (see Legend/Labels command on the Text menu) may now be up to 40 characters in length.
   
• Dense Grid Lines selection is now properly saved to preference files.

• Corrected a few problems with Dense Grid Lines. If you had previously specified a tick mark interval to use before selecting Dense Grid Lines, this feature did not work properly. Also, if the tick mark interval was small enough that DPlot would skip drawing numbers at one or more intervals (to prevent numbers from overlapping), the dense grid lines associated with the skipped intervals were not drawn. Both of these problems are fixed.
   
• Creating a new 3D plot while an XY plot window was open fouled up the data structures for the XY plot and made it unusable.

25 August 2002
Version 1.7.1

• Added /nonag commandline switch to eliminate the startup nag dialog for the evaluation version. The primary reason for adding this switch is to allow the C and Visual Basic demo programs to work properly with the evaluation version. It is not recommended for general use as it will hide the remaining evaluation period from the end user.
   
• Added Triangle plot option. See example file ex14.grf in the distribution.
   
• Fixed a precision problem with the Add a Constant to Y and Multiply Y menu commands that resulted in the operation not being performed on the first and/or last points in a curve.
   
• Fill Between Curves now allows you to select a single curve. In this case the area formed by connecting the first and last points in the curve is filled with the selected pattern. In this way you can create arbitrarily complex shaded areas on your XY plots.
   
• Added menu commands (see View menu) to hide/show curves, which might be useful on crowded plots. These features are also available via drop-down menu when right-clicking on the legend.
   
• Added Move/Copy Curves command (see Edit menu), which allows you to easily move or copy multiple curves from one document to an existing or new document. If all curves are moved (rather than copied) from a document, the document window is automatically closed.
   
• Added HideCurve, ShowCurve, and MoveCurves DDE/macro commands, which correspond to the new menu commands mentioned above.
   
• Added FileNewEx DDE/macro command, which allows you to set the caption of the new document and control whether this document becomes active or not. This is a handy addition if your application uses multiple MoveCurves commands to copy curves from several documents to a single new document.
   
• Fixed a bug with commandline options. Previously if you specified a preferences file using the /s switch, and that switch was the last parameter specified, then the changes dictated by the preference file did not take effect until you performed some action that caused the plot to be redrawn.
   
• User-specified tick mark intervals were not saved to preference files. If you specified user-defined tick mark intervals before saving a preferences file, DPlot might have crashed when later re-opening that file due to the tick intervals being set to 0.
   
• Plot extents (specified with Extents/Tick Marks/Size command) were not saved to preference files. This omission was by design, but a friendly user talked us into it.
   
• Several minor formatting changes to new box-and-whisker plots and dot graphs, plus one bug fix: the lower limit of the box on median-based box-and-whisker plots was drawn in the incorrect location for all but the first data group.
   
• Corrected a problem with contour plots built from random 3D points. In previous versions, the triangulation routine ungracefully exited if all input points were collinear. This was particularly a problem with the DDE interface, since the calling application might send data values one row or column at a time. In this version DPlot checks for all points being collinear and skips the triangulation (and doesn't attempt to produce a plot).
   
• Added XYZEx and XYZRegen DDE/macro commands. XYZEx is identical to XYZ with an additional parameter that specifies whether DPlot should triangulate and replot the data. This is especially useful if plotting from a Microsoft Excel VBA routine, which limits the maximum command string length to 256 characters. Previously if you used XYZ to plot data from a rectangular grid from Excel, you would most likely encounter errors due to all points sent being collinear. XYZEx is quite a bit more efficient than XYZ with large data sets, because you can instruct DPlot not to attempt to triangulate the data until you are ready to do so. XYZRegen forces DPlot to triangulate and plot the existing data. This command will most commonly be used after a series of XYZEx commands.
   
• Added a method for retrieving the caption of the last document created in DPlot from another program. This feature is useful if your application moves data from one plot to another. Although you can specify the caption of a document when it is created, DPlot will append a numeric suffix to that caption if a document with the same caption already exists, so it is fairly easy for your application to become confused about which document is which. The following lines of Visual Basic code retrieve the last new caption and place it in the text of "<control>" (a text box or label):
   
  <control>.LinkTopic="DPLOT|System"
  <control>.LinkMode=2
  <control>.LinkItem="LastNewCaption"
  <control>.LinkRequest
  <control>.LinkMode=0
   
• Corrected a scaling problem on XY plots that used multiple independent axes on a logarithmic scale. If the extents of either axis were not integer powers of 10, the second axis was often drawn incorrectly.

15 July 2002
Version 1.7

• New data type and corresponding plot types: this version includes box-and-whisker plots and dot graphs for one or more groups of 1D data.
   
• File>New menu entry now opens a submenu allowing you to specify the plot type: XY plot, 1D statistics plot, or 3D plot with random points. Previously it was not possible to start a 3D plot with random points from scratch in DPlot.

Several changes to 3D plots:
 

• Corrected a problem with random 3D points. In previous versions, DPlot happily accepted two or more points with identical X and Y components. This did not cause any problems with the triangulation, which ignored the 2nd and all subsequent coincident points. However, this situation caused DPlot to crash when Generate mesh was selected. In this version DPlot removes points with identical X and Y components, and tells you it has done so.
   
• Generate mesh now allows you to forego extrapolating values outside the triangular mesh.
   
• Generate mesh allows you to specify the number of additional data points used to estimate partial derivatives at the input points. In most cases the default value of 4 works nicely. However in some cases more points are needed to smooth the resulting plot.
   
• Improved several inefficiencies in the Generate mesh command, making this feature run considerably faster, particularly with a large number of input points and/or a large generated grid.
   
• The same options for specifying axis extents, tick mark interval, and plot size that are available for XY plots are now also available for both 2D and 3D contour plots.
   
• Added a Paste command for random 3D points. The Paste command assumes that the clipboard contains ASCII text representations of X,Y,Z triplets. These triplets will be added to an existing plot, and the plot will be re-triangulated.
   
• Added XYZ macro/DDE command, which allows you to add one or more X,Y,Z triplets to an existing contour plot consisting of random 3D points.
• Bug fix: Depending on the order that DPlot found Generate plugin dll's on your hard disk, the corresponding menu commands may have pointed to the incorrect plugin.
   
• Bug fix: Corrected a minor problem with the custom color picker control that caused it to use the incorrect font the second time the control was created.

24 June 2002
Version 1.6.9.12

• DPlot will now accept a "curve" consisting of a single data point, and allow you to create such a curve using Edit>Edit Data.
   
• Added a text formatting option for enlarging one or more characters in a text string. This might be useful for equations, particularly those involving integrals or summations.
   
• Text formatting options used in the title lines, axis labels, and legend are now also available for notations.
   
• Added NumTicks and TickInterval macro/DDE commands.
   
• For Visual Basic users, a new XYXY DDE command is considerably faster than all other VB methods of sending data to DPlot. Like the other methods, this command sends data values as character strings and so isn't as fast as sending binary data (as in the C demo), but for reasonable size data sets I believe you'll be pleased with the results. Thanks to Bill Bracco for the suggestion.

16 June 2002
Version 1.6.9.9

• Several changes to the C and VB demo programs: The VB example contained a bit of outdated information that prevented the code from launching DPlot correctly. The VB example has also now been compiled so that users w/o VB can see what's possible. The C example now allows you to retrieve a bitmap of the plot last produced by the demo and displays that bitmap. This of course isn't particularly useful for the demo but may give you ideas for your own applications.
   
• Eliminated a source of confusion in the Point Labels dialog box. In previous versions the label descriptions in the Select Label dialog were set to initial values and never updated, leading many users to believe that the curve number and point number selections were malfunctioning.
   
• Corrected a bug in the rendering code for random 3D points drawn with shaded bands. In previous versions, triangles that were scaled to a height of 1 pixel caused a divide by zero error and crash.
   
• Corrected two problems with text notations. Deleting the first notation caused DPlot to crash. Deleting a note that was "Button-activated" left the non-functioning button on the plot.

• AverageAndReplace is identical to AverageAllCurves, but deletes all pre-existing curves after finding the average.
   
• InfoInterpolate displays the Interpolate dialog.
   
• InfoScan displays the Scanning Points dialog for the selected curve.
   
• MenuHide and MenuShow do exactly what you'd expect. If using MenuHide you should also hide the toolbar with ViewToolbar.
   
• SetWindowPos allows you to set the size and position of either the main application window or of a child document. It also allows you to make the main application window "stay on top".

1 June 2002
Version 1.6.9.7

• Bug fix. If Dense grid lines was selected on a log scale, and the upper extent of the scale was not an integer power of 10 (5, for example), then the intermediate grid lines were drawn outside the limits of the plot.

23 May 2002
Version 1.6.9.6

• Minor fix to a bug introduced in 1.695: When presenting a list of curves in a list box, older versions displayed the entire legend text for a curve, including formatting codes for subscripts, superscripts, etc. Version 1.695 cleaned up those list entries by eliminating those formatting codes, but did a poor job of it. Under some circumstances this "fix" resulted in nonsense entries in the curve list.

21 May 2002
Version 1.6.9.5

• Added a Z axis label input for contour plots. The label is only drawn for plots viewed in 3D with Draw Axes checked.
   
• Added an option to always use the displayed colors for printed output (rather than using a separate printer color palette). See Options>General.
   
• Text labels may now include bold, italic, and underline attributes as well as subscripts, superscripts, and symbols.
   
• Added Microsoft Excel macro examples to the distribution.

• ForFilesIn may now be used to append files to the same document, rather than opening each file in a separate document window.
   
• FileOpen, FileAppend, and the ForFilesIn macros handle long filenames a bit better than previous versions.
   
• The Directory macro command now works correctly in conjunction with FileOpen and FileAppend.
   
• Fixed macro editor so that opening too many document windows with a ForFilesIn loop will abort the macro, rather than pounding you with a continuous stream of error messages for all remaining files in the loop.
   
• Added several new DDE/macro commands: Contour3D, ContourAxes, ContourGrid, ContourLevels, ContourView, GetPreferences and UseNameAsLegend. See the Help topic Executing DPlot commands from another application for more information.
   
• Programmers may now add a series of DDE execute commands to the end of the data for your XTYP_POKE transactions when operating DPlot via DDE from another application. The main result of this change is that you may now completely control the appearance of a new plot generated by another program in a single step, without causing DPlot to generate needless document window updates. Programmers should see the demo.c demonstration program for an example.

• In previous versions the "Use Name as Legend" feature did not work particularly well with the File>Append menu command, and resulted in a faulty legend.
   
• Fixed a program-crashing bug that sometimes occurred when closing an XY plot window then opening a contour plot.
   
• A roundoff error in the 3D routines caused an inconsistency in appearance between 3D and 2D views.
   
• Tabstops in notations are handled a bit differently and should now be drawn correctly for all tabstop values. In previous versions the code was prone to clipping tabbed text if the tabstop value was not a multiple of 8.
   
• Added imagehlp.dll to the distribution for Windows 95 users who do not already have this file. This change will not affect users of other operating systems.
   

27 March 2002
Version 1.6.9

• For grain size distribution plots, you may specify which sieve size labels are drawn rather than allowing DPlot to make the decision for you. You can also elect to draw heavy dashed vertical lines at the material type boundaries. See Options>Linear/Log Scaling>Grain Size Options. Thanks to Jim Robertson for the suggestions.
   
• Zoom is now enabled for 2D contour plots generated from random 3D points.
   
• 3D data on a rectangular grid (as opposed to random 3D points) may now be saved as a CSV (comma-separated values) file.
   
• The Specify Columns to Plot dialog for multi-column input files now shows the actual column headings (if present in the file) in addition to the less useful "Column 1", "Column 2", etc.
   
• Unlimited number of text notations.
   
• A new triangulation algorithm for random 3D points has been implemented and is insanely faster than the previous method for a large number of points. By way of example, triangulation of 100,000 points now takes about 1.6 seconds on a 1.4Ghz PC while the previous version took about 17 minutes for the same data. The comparisons are even more dramatic for larger data sets.
   
• All contour plots now use the limits specified on the Contour Options dialog. Previously, shaded band plots divided the Z extents of the data evenly and ignored user input for limits.
   
• You may now edit up to 16384 X,Y pairs using the Edit Data command. The previous version was limited to 1024 points.
   
• The code now does a much better job of using the extents you specify with Extents/Tick Marks/Size.
   

17 February 2002
Version 1.6.7

• Error bars. Errors may be expressed as absolute values or as a percentage of the amplitude.
   
• Fixed a couple of bugs introduced in last interim release: Options>General options were not properly preserved, and unchecking "Use thousands separator" on the Number Formats dialog caused the program to crash.
   

6 February 2002
Version 1.6.4

• Added interface for file export plugins. See the Help file for more information.
   
• Licensed version is now distributed separately, and includes 5 new plugin modules that extend DPlot's functionality. See the Features page for more information.
   
• 3D Plot changes:
  • Added a global option to automatically adjust the X, Y and Z scale factors of contour plots such that the plot is square in the XY plane and the Z extents appear to be roughly 1/2 that of X and Y. See the General command on the Options menu. This might be useful if you frequently plot data sets that have X and Y in different units or if the extents are quite a bit different. Previously, DPlot made the adjustment to X and Y scale factors automatically only if the X and Y extents differed by a factor of 10 or more. All scale factors may be changed on the Contour Options dialog, regardless of whether this option is set or not.
     
  • Added an Apply button to the Contour Options dialog that allows you to see the results of your changes without closing the dialog.
     
  • File type K (random 3D points) may now contain 3 title lines and X and Y axis labels.
     
  • DPlot now checks file type K (random 3D points) to see whether all data values lie on a rectangular grid. If so, it uses that information to triangulate the surface rather than the much more compute-intensive general purpose triangulation code that it previously used. For large data sets this change makes a huge difference in processing time.
     
  • Contour plot settings are saved to preference files. Thanks to Nolan Davis for all of these suggestions on 3D plots.
     
• Commandline interface has been improved in that you are no longer limited to a single commandline parameter. You may now specify a preferences file in addition to multiple files to open. NOTE: The nag screen of the evaluation version prevents the commandline parameters from working correctly if DPlot is not already running. The licensed version (which does not display the nag screen) does not have this limitation.
   
• Fixed a bug introduced in version 1.6 with the new Undo feature. "Data processing mode" did not work properly in that version. Thanks to Angela Eubanks for pointing out the problem.
   
• And another Undo-related bug... inches/mm selection in the "Extents" dialog did not function correctly.
   

27 January 2002
Version 1.6.2

• If a fileimport plugin failed because the X and Y arrays were too small, DPlot botched up the attempt to resize those arrays and try again.
   
• Line and symbol styles for an existing plot were wiped out when calling a plugin under some circumstances.
   

14 January 2002
Version 1.6

• Undo feature allows you to undo the last 8 operations. Since individual macro commands cannot be undone, a Saveundo macro command was added to preserve the plot state before running macros.
   
• You may specify the frequency of symbols, rather than automatically drawing symbols at every point.
   
• Added an option to each of the function commands (Y=f(X), etc.) to prevent divide by zero errors. DPlot has always gracefully trapped a divide by 0. The difference is that you may now automatically shift the independent variable by a small value so that the error doesn't occur. This might be useful for plotting functions that would otherwise result in an error at a specific value, e.g. sin(x)/x at x=0.
   
• Added "Pi Multiples" and "Pi Fractions" number formatting. Thanks to Brian Smither for the suggestion.
   
• DPlot accepts "PI", "pi", or "Pi" as the constant 3.1415926... in each of the 3 function generation menu commands.
   
• Relaxed the test for constant spacing a bit. Some operations (FFT in particular) require that a data record have a constant spacing, so DPlot checks for this quality when you use one of those commands. For a very large number of points (1 million or so), there is an inherent precision problem with determining whether the entire record has a constant spacing. (This is not a problem with digital recorder files or other file formats which by definition have a constant spacing.) In this case DPlot would report "This feature requires the data values to have a constant spacing. Note: This error message may be the result of inadequate numerical precision." The error message is correct, but of course doesn't solve the problem. This version will successfully test at least 2 million points for a constant interval.
   
• Added X and Y scale factors to the contour plot options. Previously, DPlot drew 3D contour plots with the same scale for X and Y, regardless of the extents in those directions. This might have resulted in an exceptionally narrow plot. Thanks to Nolan Davis for the suggestion.
   

12 December 2001
Version 1.5.2

• You may now include subscripts, superscripts, and characters from the Symbol font (Greek characters, trademark symbols, etc.) in the plot title lines and axis labels.
   
• Bug fix to Y=f(Y1,Y2) command and any other command that operated on 2 curves. Previous versions crashed in some circumstances due to a roundoff error. Thanks to Brian Smither for pointing out the problem.
   
• Bug fix to zoom code. Previous versions were prone to crash when a plot used multiple Y axes.
   
• Multiple-column format files had an arbitrary limit of 16 columns (X + 15 Y columns). This version has no limit (other than the maximum number of curves per plot, which is currently 100). Thanks to Henry Young for pointing out this problem as well as the zoom bug.
   
• Paste code balked at trailing spaces in the text and reported a not-so-helpful "Error reading numbers".
   
• Several menu commands have been tossed out in favor of a single input dialog for specifying plot extents, tick mark interval, and plot size. You can now specify a tick mark interval directly, which has been a confusing process in the past.
   
• Better support for export of 2D contour plots to .PDF file using Adobe Distiller. Please note that PDF Writer produces decidedly chunky contour plots, and currently I have no idea what the problem is. In any case, Distiller doesn't have this problem and works quite well.
   
• Fixed several problems with the commandline interface, which was broken in the last several versions.
   
• Changed the file import plugin interface a bit to distinguish between allowing/disallowing the selection of multiple files for one plot. (As with all other file types, to select multiple files in the "Open" dialog box, press and hold the Shift key while selecting.) If you're interested in this sort of thing be sure to download the new plugin examples.
   
• Print margins are saved to preference files (using File>Save Preferences).

14 August 2001
Version 1.5.1

• Bug fix to Paste code. Previously the number of data sets that could be copied from the Clipboard was limited by the length of a character string used to read one row of values. This effectively limited DPlot to pasting between 3 and 13 new curves. That limitation is now removed, and you can paste up to 100 data sets from 101 columns (X in the first column). Thanks to Ross Ashman for pointing out the problem.
   

9 August 2001
Version 1.5

• For instrumentation gurus - a fix for problem Pacific 5700 files. Alan Bell pointed out that some Pacific files claim 16 data segments though the file actually contains 15. In this release DPlot ignores the number_of_posttrigger_segments field in the header and uses the file size to determine the correct number of segments. Not an ideal solution, but this is about all we can do if the header info is wrong.
   
• Fixed a problem with the header info in DPlot macros that was carried over from previous versions of DPlot. Distributed macros (as well as any you create) should work fine now.
   
• A good suggestion from Nancy Strong: "Axes at 0" menu command forces axes to be drawn at X=0 and Y=0 (if those values are within the plot) rather than always drawing axes from the lower-left corner. This option applies only to linear X, linear Y plots.
   
• You can plot a function X=f(T), Y=g(T), where T is an independent parameter. This compliments the Y=f(X) command nicely, but more importantly the formula features of DPlot (Y=f(X), X=f(T),Y=g(T), and new Z=f(X,Y)) do not require the presence of Microsoft Excel. This version of DPlot uses the MindFly Function Parser from Andreas Hartl to parse formulas. Big thanks to Andreas for this excellent tool.
   
• DPlot can now work with 3rd-party plugins to read custom file formats or manipulate data in some way that is not currently handled by DPlot. Source code is provided with plugin examples.
   
• The big one... DPlot goes 3D. DPlot can produce 2 types of contour plots - contour lines or shaded color bands representing different Z values. Input data can be random 3D points or Z values on a rectangular grid. Random 3D values can be read from a file, pasted from the Clipboard, or sent to DPlot via DDE (see the DEMO.EXE program in the /C folder below DPlot). Gridded data can be produced via the new Z=f(X,Y) menu command or, again, via DDE.

  For random points, DPlot produces a convex mesh of triangles and assumes each triangle is planar. Values outside the mesh are not plotted.

  Starting with randomly-spaced points, you can generate a smoother interpolated grid using the "Generate Mesh" command on the Options menu.