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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:

LIVEPLOT Menu Contents

File Menu

Checkbuttons are provided for each phase to determine if tick marks are shown. See the Options/"Configure Tickmarks"menu item for information on tickmarks
This allows a histogram to be selected to be loaded
Update Plot
The causes LIVEPLOT to read read the current histogram again from the datafile
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.

File Menu

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 plot entries
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 (see below).
Save Options
Causes many of the options set in this menu to be saved in the .gsas_config file.


Plot zooming 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."

Reflection indices 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 equation for cumulative chi2 function.

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 present.

The following variables control how LIVEPLOT functions and can be customized by changing their values in the localconfig and .gsas_config files:

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.
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.
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 set automatically.

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 Windows and UNIX.

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) $