MSEL, NIST Center for Neutron Research Materials Science and Engineering Laboratory NIST Center for Neutron Research National Institute of Standards and Technology
Home Instruments Science Experiments SiteMap

NCNR Frequently Asked Questions for GSAS & EXPGUI

This page logs some problems and their solutions using EXPGUI & GSAS. Please contribute more wisdom (preferably in HTML format) for inclusion on this page by sending it to crystal@NIST.gov

Summary of Questions

  1. I get an error, "ISAM record with KEY = "" has problems."
  2. Adding an atom in EXPEDT causes the program to bomb.
  3. POWPLOT and other graphics programs fail to run with an error about missing fonts (Windows)
  4. LIVEPLOT reports an error "Command BLT_ZoomStack not found"
  5. When I run EXPGUI, I see only some of the "panes".

Questions and Answers

  1. I would like to do Rietveld refinement on some data, but when I read the data/instrument parameter file I get an error, "ISAM record with KEY = "" has problems." How do I fix this?

    This problem used to occur more frequently, but since May 2000, GSAS has become more tolerant on line length so this error is seen less often. Here is what causes it:

    GSAS experiment, data & instrument parameter files are expected to have 80 characters/line plus a carriage return and a linefeed (that means really 82 characters/line). In the case of data & instrument parameter files, the length of the files is checked to see if it is divisible by 82. If not, then GSAS will attempt to fix this by copying the file to a temporary file and then use the temporary version of the file for input. This slows down the programs that must do this (primarily EXPEDT, POWPREF & RAWPLOT) but is not worth worrying about. If the file is not correctly formatted but by accident does have exactly n*82 bytes in the file, GSAS will not try to reformat the file and you might get an error like the one above. EXPGUI usually reformats files for you automatically, but if you need to, there is an explicit file conversion program in GSAS (CNVFILE) that takes standard ASCII files and writes exactly 80 characters/line plus a carriage return and a linefeed.

    Note in the past, GSAS direct access files (histogram, instrument parameter and experiment files) in Unix were 80 characters/line with no carriage return or linefeeds. Since sometime in 2001(?), these files are the same on all platforms, with 82 characters/line.

    The versions of GSAS distributed in ~May 2000 and later can convert data and instrument parameter files (by not experiment files) "on the fly" with a minor loss in efficiency. Note that for DOS, files are checked by dividing the number of bytes in the file by 82. If is divisible then the file is not converted. EXPGUI reads and convert files for both platforms.

  2. Adding an atom in EXPEDT causes the program to bomb: I put in a line that looks something like: 
               I N O .23 .23 .40 1
    and the program bombs. The window just disappears and next time I start up expedt, I am informed that the program bombed.

    This problem is caused in DOS/Windows when EXPEDT cannot locate the data file with information about scattering factors. If you are using PCGSAS or GSAS.BAT, this probably means you have not set the GSAS environment variable correctly (see the GSAS readme file).

  3. POWPLOT and other graphics programs fail to run with an error about missing fonts (Windows)

    This error was found by someone running a pretty old version of GSAS (more than one year) with EXPEDT and tkGSAS. You need to use a recent verion of GSAS (1998 or later).

  4. LIVEPLOT reports an error along the lines of "Command BLT_ZoomStack not found"

    This happens when the BLT package file has not been built correctly. You will need to fix the pkgIndex.tcl file in the blt2.x directory.

    Here is an example pkgIndex.tcl, where libBLT.so and bltGraph.tcl are both in the same directory as the pkgIndex.tcl file (in this case /usr/local/lib/blt2.1/) 

    package ifneeded BLT 2.1 [list tclPkgSetup $dir BLT 2.1 {{
    libBLT.so load {barchart bgexec bitmap bltdebug busy drag&drop graph 
                    htext spline table tilebutton tilecheckbutton tileframe 
                    tilelabel tileradiobutton tilescrollbar tiletoplevel 
                    vector watch winop}} {
    bltGraph.tcl source {BltActivateLegend BltAddBindTag BltBox BltFindElement
                    BltFlashPoint BltGetCoords BltMarkPoint BltPopZoom 
                    BltPushZoom BltRemoveBindTag BltResetZoom BltSetZoomPoint 
                    BltZoomTitleLast BltZoomTitleNext Blt_ActiveLegend 
                    Blt_ClosestPoint Blt_Crosshairs Blt_PrintKey Blt_ZoomStack
                    bltmanzoom}}}]
    Here is an example pkgIndex.tcl for BLT 2.4 where bltGraph.tcl, libBLT24.so and pkgIndex.tcl are all in /usr/local/lib/blt2.4 
    package ifneeded BLT 2.4 [list tclPkgSetup $dir BLT 2.4 {
    {libBLT24.so load {blt::barchart blt::beep blt::bgexec \
                   blt::bitmap blt::bltdebug blt::busy blt::cutbuffer \
                   blt::drag&drop blt::graph blt::htext blt::spline \
                   blt::stripchart blt::table blt::vector blt::watch \
                   blt::winop}} {
     bltGraph.tcl source {Blt_ActiveLegend Blt_ClosestPoint Blt_Crosshairs \
                       Blt_PrintKey Blt_ZoomStack \
                       blt::ActiveLegend blt::ClosestPoint blt::Crosshairs \
                       blt::PrintKey blt::ZoomStack}}}]

  5. When I run EXPGUI, I see only some of the "panes". The Constraints & Preferred Orientation panes described in the documentation are not present.

    The EXPGUI software needs a Tcl/Tk package called BWidgets to display the Constraints & Preferred Orientation panes.

    EXPGUI with the BWidget package


    If present, all "tabs" are shown, as is seen above. The BWidgets package also allows labeling of boxes (like the area circled in yellow).

    EXPGUI without the BWidget package


    If this package cannot be loaded, the boxes are not labeled (as is seen above), only the first 5 tabs are shown, and the tabs have a font that is a little less attractive (IMHO).

    The EXPGUI software is distributed with the BWidget package, so this usually works just fine "out of the box." Problems have been noted when some of the files that belong in the BWidget-1.2.1 subdirectory of the expgui directory were accidently duplicated in the expgui directory (in particular file pkgIndex.tcl). If you have this bug, confirm that you have not done this, and if necessary, delete or rename the expgui directory and reload them again.

GSAS is written by: Allen C. Larson and Robert B. Von Dreele MS-H805, Los Alamos National Laboratory, Los Alamos, NM 87545. Problems, questions or kudos concerning GSAS should be sent to Robert B. Von Dreele at vondreele@anl.gov

GSAS is Copyright, 1984-2002, The Regents of the University of California. The GSAS software was produced under a U.S. Government contract (W-7405-ENG-36) by the Los Alamos National Laboratory, which is operated by the University of California for the U.S. Department of Energy. The U.S. Government is licensed to use, reproduce, and distribute this software. Permission is granted to the public to copy and use this software without charge, provided that this notice and any statement of authorship are reproduced on all copies. Neither the Government nor the University makes any warranty, express or implied, or assumes any liability or responsibility for the use of this software.

Comments, corrections or questions: crystal@NIST.gov
Last modified 09-February-2005
$Revision: 1.6 $ $Date: 2004/10/05 18:22:25 $