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The Portable CMPR program

(Revised for distribution on 11/2001.)

The most recent additions are noted with , while noteworthy revisions added in the last few revisions are marked with .

CMPR is a multipurpose program that can be used for displaying diffraction data, pattern indexing and peak fitting and other nifty stuff. I started writing this program as a replacement for a VAX program that I also called CMPR, but it has evolved to have quite different features. I consider CMPR to be my "swiss army knife" for diffraction. Any useful manipulation that I need will probably end up here eventually. Other people have also started adding their own modules to CMPR. I will gladly accept contributed code to add new features to CMPR. If you want to do this but need some help getting started, please contact me.

CMPR requires the Tcl/Tk and BLT packages. Starting with this version, CMPR no longer uses Tix for fancy GUI features, instead it uses the BWidget package. The BWidget package is included in the CMPR code, so it does not need to be installed within Tcl/Tk.

CMPR is developed and tested on UNIX computers (SGI and Linux). It also runs on computers with the Windows-95 & Windows-NT (V4.0) and Windows-98 operating systems, but I do little Windows testing myself. It will also probably run on Macintosh computers, but it will require some work on porting parts of the BLT package as well as some AppleScript work. (Any volunteers?)

The program incorporates several small FORTRAN programs containing routines borrowed (mostly with permission) from lots of sources:

Mailing List

If you use CMPR, please
ask to get on the mailing list. By doing this, you will hear about updates (but not very often; nor will you get e-mail through this list about anything else). Having a list of users will also help me show my management that these tools are valuable to the scientific community, which might encourage more CMPR development.

Installation

See the appropriate link for: UNIX or Windows-95 and -NT installation instructions (files included in the doc/ directory).

Documentation

The following sections describe how the program works and the various modes within the program. Each section has a link labeled GUI or PLOT to show appropriate to screen displays, or a single page shows all. .

Mouse actions

Keyboard Shortcuts

Read (GUI)

Write (GUI)

Plot (GUI and PLOT)

Rescale (GUI)

Combine (GUI)

HKLGEN (GUI)

EditCell (GUI or PLOT)

Fit (GUI or PLOT)

Once a refinement has been done, the peak positions in the peak list buffer are updated also a "Undo last cycle" button is shown. Pressing this button resets the values in the various boxes to their values from before the refinement (it does not change the values in the peak list buffer). If you want to save the fitted curve, the "Store Fit" button creates a buffer with the current fit result.

The GPLSFT program can use the Finger-Cox-Jephcoat correction for peak asymmetry. For this correction, three terms must be known: the diffractometer radius, the half-height (or half-width) of the sample and of the detector. Values may be specified in any consistent units. (NIST would prefer that you use metric units, of course.) While these values can be refined, do so with care: do not refine too many variables at the same time, use a small number of cycles and set the damping factor to a small number.

By default fit results are shown superimposed on the plot of the fit, but the results can be placed in a separate window by deselecting the "Report fit results in plot window" checkbox on the Display options page.

Peaks/Smooth (GUI)

Index (GUI or Results Window)

Options

Help (GUI)

Customizing

CMPR is designed to be expanded. Read the code and send me any extensions you create. Have fun!

Initialization files

Reading directly from GSAS experiments

Using the Example File Formats

Supporting Additional File Formats


grace

Grace is a nice WYSIWYG 2D plotting tool for X Windows. Many UNIX users will be familiar with a prior version of grace, known as xmgr. It is distributed under the terms of the Free Software Foundation public license, and may be downloaded for free. Grace runs on practically any version of Unix. As well, it has been successfully ported to VMS, OS/2 and Win9*/NT. Use in Windows may be somewhat clumsy, as a X-Windows package is required. See the grace homepage at http://plasma-gate.weizmann.ac.il/Grace/ for more information.


Neither the author nor the U.S. Government makes any warranty, expressed or implied, or assumes any liability or responsibility for the use of this information or the software described here. Brand names cited here are used for identification purposes and do not constitute an endorsement by NIST.

Comments, corrections or questions: crystal@NIST.gov

$Revision: 1.6 $ $Date: 2001/11/09 19:01:47 $