This page documents the LIVEPLOT utility in the EXPGUI package.
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. Since TCLDUMP has been
included in GSAS since April of 2000, it is assumed that this is now the case.
Some of the features available in LIVEPLOT are:
- The plot is updated automatically after each refinement run
- The plot can be zoomed, by clicking on the corners of the
area to be magnified.
The units used for plotting histograms can be selected. Choices are:
native units (2Theta/TOF/KeV); d-space (A) or Q (A-1)
The background (fixed plus fitted) can be plotted or can be subracted.
Reflection tickmarks can be displayed in a variety of formats
LIVEPLOT can be coupled to the LOGIC or CMPR programs, so that
peak positions from an ICDD entry or for an arbitrary unit cell and
spacegroup can be shown superimposed on the "Rietveld plot."
Reflection indices (hkl values) can be shown for tickmarks
The cumulative chi2 function can be plotted.
LIVEPLOT Menu Contents
- Checkbuttons are provided for each phase to determine if tick marks
are shown. See the Options/"Configure Tickmarks"menu item for information
- This allows a histogram to be selected to be loaded
- Update Plot
- The causes LIVEPLOT to read read the current histogram again from
- Make PostScript
- Creates a low quality PostScript file containing the LIVEPLOT
output. See the Options/"Set PS output" button for where the file is created.
- Configure Tickmarks
- Tickmarks can be placed automatically, similar to their
placement in POWPLOT or can be drawn one height to another. The default
is for lines to be draw from "-Inf" to "Inf", which creates lines from the
bottom to the top of the plot. The options for each phase allow the line to be changed between solid and dashed, color of the line can be specified and
the vertical placement of the tickmarks can be specified. The "show" flag,
set in the File/Tickmarks menu can also be changed here.
- Obs symbol
- This brings up a menu where the symbol type and size for the
observed data points can be selected.
- X units
- The x units can be selected here. The choices are
"as collected" (2Theta/TOF/KeV), d-space (A) or Q (A-1)
- Y units
- The intensity values can be normalized by the incident spectrum
(for energy dispersive methods).
- HKL labeling
- This brings up a menu that selects how long hkl values are shown
before they are erased (0 means that they are not erased), the size of the
labels and the width around the mouse that is searched for matching
reflections. If requested using the "Separate window for hkl labels"
option, labels are also show in a separate window.
- Subtract background
- The background is always shown, even when subtracted
- Include legend
- The legend is the optional box in the upper left that defines the
- Set PS output
- For UNIX this allows the file to be sent directly to a printer
or can be saved in a file. For Windows, a file must be written.
- Raise on update
- This causes the plot to be placed on top of other windows, if partially
obscured, when the plot is updated. At this time, this option does not
work in Windows-NT and -2000.
- Cumulative Chi2
- The causes the Cumulative chi2 function to be defined
- Save Options
- Causes many of the options set in this menu to be saved in the .gsas_config file.
When the left (usual) mouse button is pressed, this defines one corner
of a region to be magnified. If the mouse is then moved, the diagonal
corner of this magnification region is defined. When the left mouse button
is pressed a second time, the selected section of the plot is magnified to
fill the entire plot.
Zoom settings are saved.
If the right mouse button is pressed, the previous zoom setting is used,
so that the left mouse button is used to "zoom in" and the right mouse
button is used to "zoom out."
are 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).
The cumulative chi2
function was first suggested by
Bill (W.I.F.) David [Accuracy in Powder Diffraction-III, 2001]
as a way to see which reflections have the greatest influence on
chi2. It is defined for point j as
Customization of LIVEPLOT
The localconfig and .gsas_config files are read, if present.
Note that some of these options are relevant only if the tcldump program is
The following variables control how LIVEPLOT functions and can be
customized by changing their values in the
localconfig and .gsas_config files:
The following variables are written to .gsas_config when
"Save Options" is used. These variables are all set from the GUI and therefore
do not need to be edited manually.
These variables define if peak positions will be shown
for reflections in phase "n". Reflections will be shown if
the value is non-zero.
These variables define the default colors for
reflections in phase "n"
These variables define if peaks will be dashed for
reflections in phase "n" (UNIX only). Lines will be dashed if
the value is non-zero.
- peakinfo(minn) and peakinfo(maxn)
These variables dictate the placement vertical position for reflection
markers, when manually placed (see expgui(autotick), below). To draw
to the edge of the screen, use -Inf and Inf.
This is set to 1 if PostScript files
will be printed and 0 if they will be written to disk (for Windows all
files should be written to disk).
This is the default for the file name used
when PostScript files will be written to disk.
This is the default for the command used
to print PostScript files (Unix only).
Sets the default value for display of the legend in liveplot and widplt.
This option shows up in the options menu item as "Raise on update."
When set to non-zero, the liveplot window is raised
(placed on top of any other overlapping) windows
each time it is updated.
This option does not seem to work in Windows-NT, but this may depend on
the version of Tcl/Tk.
Symbol for observed data points. Valid choices are square, circle, diamond,
plus, cross, splus and scross.
Size for the symbol for observed data points. A value of 1 corresponds to about 1/8 inch
(about 3 mm).
When hkl values are loaded (using tcldump) and reflections are labeled, reflections
can be labeled using a Shift-Left-Mouse click. All labeled reflections within expgui(pixelregion)
pixels of the mouse position are assumed to be overlapped and are labeled.
The time in seconds before reflection labels are removed. A value of zero means that reflections
must be deleted manually (Shift-Right-Mouse).
A size for reflections labels in pixels.
If this variable is non-zero, reflection indices are shown in a box.
If this variable is non-zero, reflection markers positions are
Installation details/External Programs
Using TCLDUMP with LIVEPLOT.
LIVEPLOT works with the standard GSAS program HSTDMP, but it works faster and is more
powerful when used with the TCLDUMP program.
Note that as of the April 2000 releases, GSAS is now distributed with TCLDUMP
included. For older versions of GSAS, note the
instructions for downloading this file can in the installation notes for
Combining CMPR and LIVEPLOT.
If you have CMPR
installed on your computer, you can use superimpose on the GSAS results
the peaks for an arbitrary unit cell. If desired, space group extinctions
can even be shown.
This is pretty neat! To enable this feature, you must have a version
of CMPR downloaded after 4 May 1998
(see the CMPR installation instructions.)
Combining LOGIC and LIVEPLOT.
If you have LOGIC
installed on your computer, you can superimpose peaks
for a entry from the ICDD/JCPDS database on a pattern in LIVEPLOT.
This is also pretty neat!
To enable this feature, you must have
a version of LOGIC downloaded after 4 May 1998
(see the LOGIC installation instructions.)
Brian Toby (Brian.Toby@NIST.GOV)
$Revision: 386 $ $Date: 2009-12-04 23:05:18 +0000 (Fri, 04 Dec 2009) $