A Graphical User Interface for
EXPGUI is a graphical interface for the
It allows two types of actions:
it can be used to directly modify the GSAS
experiment file with a graphical user interface (GUI) and
it can be used to invoke the programs inside the
GSAS package such as EXPEDT, GENLES, FOURIER...
These programs can be run from a menu or in many cases by pressing buttons.
This documentation describes the different actions that
can be accomplished with the different panes and the
contents of the menus. Other documents about EXPGUI are:
Installation notes for
Customization notes, a list of warning, error and informational messages
and two example tutorials: for
Note that screen images in this document are not updated as frequently as the
A. Experiment file editing
When an experiment (.EXP) file is read, a copy is made in local
computer memory. The values in memory can then be edited
by selecting different
panes ("pages" or "panels") from the tabbed list, where
each pane is reserved for a different section of the .EXP file.
The changes values are written back out to the .EXP file when the
"File/Save" or "File/Save as" menu bar options
are used. The .EXP file is also automatically written before running any GSAS
programs, such as GENLES or EXPEDT.
The notebook pane tabs.
More information about each pane can be found using the links below.
A.1 Least Squares (LS) Controls Pane
A.2 Phase Pane
A.3 Histogram pane
A.4 Scaling pane
A.5 Profile pane
A.6 Constraints pane
A.7 Preferential Orientation Pane
Values changed in the entry boxes in these panes are
immediately transferred to the "in memory" copy of the .EXP file, unless
there is an error in the typed value, (for example if "1..0" is typed, or
"1.5" is typed where an integer is expected.) When a value is invalid, it is
not saved. In this case, the text is turned red, to indicate
that an error is present, as shown in the figure to the left, where "90.000x"
has been entered for alpha.
B.1 Multiple Histogram Selection
This mode allows parameters to be changed for groups of
When the "Multiple Histogram Selection" mode is off,
it is possible to modify parameters
and refinement flags for only a single histogram, but
the other settings allow groups of histograms
to be selected and modified.
(see Mouse Actions).
It does not make sense, however, to globally modify
instrument-related parameters and flags for different
So global actions can be limited to a single class
of histogram types (e.g. TOF, CW Neutron,...), which
allows these parameters to be set for groups of
similar histograms. Thus, if this mode is set to "All"
the Histogram and Profile panes are disabled.
The setting for "Multiple Histogram Selection" mode is
displayed above each histogram selection box and is
selected using the "Multiple Hist. Selection" item on the
Options menu to create a submenu or by clicking on the display.
Note that another option in this "Multiple Hist. Selection"
submenu is an option "Group Phases Together" that controls how
EXPGUI treats phases having
the same profile type that is used when multiple histograms are selected. If
the "Group Phases Together" option is on, then the refinement flags for
all phases with the same histogram types are grouped together, when possible.
If this option is off, phases are treated separately.
If the left mouse button is used to click on the selection mode display,
the mode is cycled between the available modes. If the right mouse
button is used, the mode is reset, to disable multiple histogram selection.
B.2 Mouse Actions
A range of atoms or (in multiple selection mode) histograms may be
selected by dragging (holding down) the left mouse button. It is also
possible to select a range by using the Shift key with the left mouse
button. To select or deselect individual entries, use the Control key
with the left mouse button. Pressing the right mouse button selects all
entries in a list.
C. Menu Commands and Programs
GSAS programs are invoked either through use of the menu bar
The menu bar.
or by "pressing" a button on the button bar. The button bar
simply provides an easy way to access commonly used
actions on the menu bar. Users can
configure the menu bar to include their own preferred actions and, with
some knowledge of the program and Tcl/Tk,
add their own commands to the menu bar or button bar.
The button bar.
A description of the EXPGUI menus follows. Use the links to obtain
more information, including a very
brief description of the function of each menu option.
Note that an option may appear under more than one menu.
C.1 File Menu
The options on the File menu as is the custom contains the commands
for reading and writing experiment files, as well as starting
and ending the program.
C.2 Options Menu
This menu contains options that determine how EXPGUI runs.
C.3 Powder Menu
This menu contains links to GSAS programs used for powder diffraction
C.4 Single Crystal Menu
This menu contains links to GSAS programs used for
single-crystal diffraction analysis.
C.5 Graphics Menu
This menu contains links to several GSAS and
two non-GSAS (liveplot and widplt)
programs used for graphical display of data and results.
C.6 Results Menu
This menu contains links to several GSAS and
one non-GSAS (lstview)
programs used for analysis of results.
C.7 Calculations Menu
This menu contains programs for useful crystallographic computations.
C.8 Import/Export Menu
This menu contains utilities for importing information into GSAS and
D. EXPGUI Utility Programs
lstview is used to browse through the GSAS output listing. It is
invoked by the "lstview" command in the GUI.
liveplot shows the observed, calculated and difference plots for powder
refinements. The plot is updated as the refinement progresses. The mouse can
be used to zoom in on sections of the plot.
Liveplot uses the BLT graphics package.
LIVEPLOT can now be enhanced to superimpose peak locations for
input unit cells or peaks from JCPDS/ICDD entries.
LIVEPLOT customization information
or read file expgui_cfg.html in the gsas/tcl/doc directory.
LIVEPLOT gets the current diffraction information by running the TCLDUMP program, if installed, or
HSTDUMP otherwise. The TCLDUMP program has been optimized for use with LIVEPLOT and offers a number of extra
options that are not available when HSTDUMP is used: plots can be displayed in the native units (2Theta/TOF/KeV), or
in d-space or Q; fixed plus fitted background curves are shown in green; if reflection tickmarks are displayed,
reflection tickmarks can be displayed by pressing "H" or "h" while the
mouse is near a reflection (holding the shift key while
pressing the left mouse button also works).
See the installation instructions for installing TCLDUMP.
WIDPLT can be used to plot the actual peak widths generated by the profile
parameters used in GSAS.
It is possible to define reference curves
that are loaded automatically.
WIDPLT uses the BLT graphics package.
Unix File Conversions
In UNIX, GSAS data, experiment and instrument parameter files are expected to
have a format with exactly 80 characters per line and no line
separators (no carriage returns or linefeeds). Files in this format
are called "Direct Access". Normal UNIX files may have any number
of characters per line and every line is terminated by a line feed character.
These files are called "sequential".
EXPGUI uses the convention that all uppercase is used for Direct Access files
while all lowercase is used for sequential files.
The Unix File Conversion menu is used to convert sequential files to
direct access for use in GSAS or to convert direct access files to
sequential, for use in standard UNIX programs, such as editors or e-mail.
Windows File Conversions
In Windows, GSAS data, experiment and instrument parameter files are
expected to have a format with exactly 80 characters per line followed
by a carriage returns and a linefeed (82 characters total per line).
Files in this format can be read in "Direct Access" mode. The Convert menu
in windows can be used to convert files into this format (it can also
convert UNIX direct access files correctly). The original version of the
file is retained and renamed.
The composition box shows the unit cell and asymmetric unit composition
for all phases in a material. Site multiplicities and occupancies are
taken into account.
Export coordinates in MSI .xtl format
The Export/exp2xtl routine writes a .xtl file, as is used in Insight-II and
Cerius2 (Molecular Simulations, Inc.). Note that spacegroups are not named
exactly the same in the two programs and the origin may need to be specified
as "origin 2", for spacegroups where the center of symmetry is not at the
origin. It is up to the user to get things right.
Delete History Records
Every time a GSAS program (including EXPGUI) is run, an entry is added to
the "history records" in the .EXP file. After 999 entries have been written,
no more can be added to the file. Further, reading large numbers of history
records can slow the GSAS programs
(this is less of a problem on faster computers). For these reasons, it may be
a good idea to prune the older history records from the file. If more than 100
history records are found in an experiment file, EXPGUI suggests that the
older history entries be deleted. Alternately the File/EraseHistory command
can be used to invoke the this option.
On the dialog the number of history records to be retained is specified.
Also, after records have been deleted, the remaining records can be renumbered
starting with 1, so that the 999 record limit is not reached.
The BLT graphics package is used by the WIDPLT and LIVEPLOT routines. If the
package can not be loaded these routines, an error message,
"Error -- Unable to load the BLT package", will be displayed. A frequent
problem is the package is installed, but not configured so that common
support routines are loaded automatically. If this is the case,
a message, "BLT Setup Error: could not access a Blt_ routine...",
will be displayed.
for more information on installation of BLT.
Praise to Larson and
Von Dreele for GSAS, Ousterhout
for convincing me to learn Tcl/Tk
and Jonathan Wasserman for helping get this project started.
Large sections of the Preferred Orientation GUI were written by
Pamela Whitfield of the NRC (Canada).
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
EXPGUI is written by Brian H. Toby of the NIST Center for Neutron Research,
with help from Jonathan Wasserman.
GSAS is Copyright, 1984-2000, by
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
EXPGUI is not subject to copyright. Have fun with it. Modify it. Write
new sections and make them available to the rest of the world.
Neither the U.S. Government nor any author 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 consitute an endorsement by NIST.
Brian Toby (Brian.Toby@NIST.GOV)
$Revision: 329 $ $Date: 2009-12-04 23:04:14 +0000 (Fri, 04 Dec 2009) $