Changeset 202 for trunk/doc

Timestamp:

Dec 4, 2009 5:02:06 PM (14 years ago)

Author:

toby

Message:

# on 2000/06/09 03:53:28, toby did:
Add Pref Orientation Section
Renumber and reorganize sections
quick revisions

File:

• trunk/doc/expgui.html (modified) (16 diffs, 3 props)

trunk/doc/expgui.html

@@ -32 +32 @@
 GSAS</A> package. 
 It allows two types of actions: 
-the different 
-GSAS</A> 
-programs such as EXPEDT, GENLES, FOURIER,... 
-can be run from a menu or by  pressing buttons, 
-and it can be used to directly modify the GSAS 
-experiment file without using EXPEDT.
-This document describes the functions in EXPGUI.
-Note that pictures on this page are not updated as frequently as the
+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.
+
+<P>
+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:
+<a name="installation"></A>
+<A HREF="expgui_Win_readme.html">
+Installation notes for Windows</A>, 
+<A HREF="expgui_Unix_readme.html">
+Installation notes for UNIX</A>,
+<A HREF="expgui_cfg.html">
+Customization notes</A> and two example tutorials: for
+<A HREF="tutorial1/index.html">
+TOF</A>
+and 
+<A HREF="tutorial2/index.html">
+constant-wavelength neutron</A>.
+Note that screen images in this document are not updated as frequently as the
 text. 
-
+<hr>
+
+<h2>A. Experiment file editing</h2>
+<P>
+Different sections of the .EXP file can be edited by selecting different 
+panes ("pages" or "panels") from the tabbed list. 
+<center><B>
+<br>The notebook pane tabs.
+<br><img SRC="panebar1.gif"  BORDER=3 >
+</center></B>
+
+<P>
+<h3>A.1 Least Squares (LS) Controls Pane</h3>
+<DL><DL>
+<p>The LS Controls pane shows information about the 
+current experiment, typically found in the EXPEDT "Least 
+Squares Controls" options. 
+<P>
+Note that the order that histograms appear in this 
+pane is determined by the 
+<a href="http:#sorthist">"Sort histograms by"</a> option in 
+the Options Menu.
+<img SRC="1.gif" align=TEXTTOP>
+</DL></DL>
+
+<P>
+<h3>A.2 Phase Pane</h3> 
+<DL><DL>
+The phase pane is used to edit information
+about the structural model(s) found in the experiment 
+file. The flags for refining the unit cell and atomic parameters,
+as well as ther damping values, 
+can be set  on this pane. Note that if a
+single atom is selected using the mouse, the information 
+for that atom can be edited. If a group of atoms is 
+selected
+<A href="#mouseactions">(see Mouse Actions)</A>
+the damping and refinement flags 
+for all the selected atoms are changed.
+<P>
+If the EXPTOOL program 
+<A href="#installation">(see the installation instructions)</A>
+is installed, buttons for adding phases and atoms will 
+appear on this pane, as seen below. If the
+program is not properly installed, no errors occur, but the buttons
+do not appear.
+<P>
+Note that the order that atoms appear in this pane is 
+determined by the 
+<a href="http:#sortatoms">"Sort Atoms by"</a> option in the Options Menu.
+<img SRC="2.gif" align=TEXTTOP>
+</DL></DL>
+
+<h3>A.3 Histogram pane</h3> 
+<DL><DL>
+The histogram pane is used to edit background
+and diffractometer constants for a histogram, as well as 
+set damping and refinement flags for these parameters.
+<P>
+If 
+<A href="#multiplehistogram">
+"Multiple Histogram Selection" mode</A> is set to "All", 
+this pane is disabled. For other settings of this mode, 
+groups of histograms can be selected and modified 
+collectively.
+<P>
+If the EXPTOOL program 
+<A href="#installation">(see the installation instructions)</A>
+is installed, a button for adding histograms will
+appear on the bottom right on this pane, as seen below. If the
+program is not properly installed, no errors occur, but the button
+does not appear.
+<P>
+Note that the order that histograms appear in this 
+pane is determined by the <a href="http:#sorthist">"Sort histograms by"</a> option in 
+the Options Menu.
+<img SRC="3.gif" align=TEXTTOP>
+</DL></DL>
+
+<h3>A.4 Scaling pane</h3> 
+<DL><DL>
+The Scaling pane is used to edit the scale factor for a 
+histogram as well as the phase fractions for each phase
+present in that histogram. Damping and refinement flags
+for the scaling terms can also be set here.
+<P>
+If 
+<A href="#multiplehistogram">
+"Multiple Histogram Selection" mode</A> is set to 
+any value other than "Off,"
+groups of histograms can be selected and modified 
+collectively.
+<P>
+Note that the order that histograms appear in this 
+pane is determined by the <a href="http:#sorthist">"Sort histograms by"</a> option in 
+the Options Menu.
+<img SRC="4.gif" align=TEXTTOP>
+</DL></DL>
+
+<h3>A.5 Profile pane</h3> 
+<DL><DL>
+The Profile pane is used to edit the profile values for 
+each phase present in a histogram as well as set 
+the refinement flags and a damping value for each phase.
+<P>
+If 
+<A href="#multiplehistogram">
+"Multiple Histogram Selection" mode</A> is set to "All", 
+this pane is disabled. For other settings of this mode, 
+profile values and settings can be collectively
+modified for groups of histograms.
+<P>
+Note that the order that histograms appear in this 
+pane is determined by the 
+<a href="http:#sorthist">"Sort histograms by"</a> option in 
+the Options Menu.
+<img SRC="5.gif" align=TEXTTOP>
+</DL></DL>
+
+<h3>A.6 Constraints pane</h3>
+<DL><DL>
+GSAS offers two types of restraints that can be included in a model. 
+So called "soft constraints" or "restraints" penalize the fit if 
+aspects of a model (for example, bond lengths) differ from selected values.
+So called "hard constraints" reduce the actual number of 
+parameters in a model,
+by grouping parameters so that a single shift (possibly scaled) is 
+applied to each parameter in the group.
+The constraints pane is used to set these "hard constraints."
+At this time the only constraints that can be set in EXPGUI are on atomic
+parameters (others can be set in EXPEDT).
+<P>
+Note that these constraints are only applied to shifts but not to the
+actual values. This means that, for example, 
+if two atoms 
+are constrained so that the shift on their occupancy is the same, but 
+the initial occupancies differ, the in occupancy difference will not change 
+as the values refine.
+<P>
+<H4>Atom Constraints</H4>
+The atom constraints editing pane appears below. Note that constraints can 
+be listed sorted by constraint number, phase number, lowest atom number or
+variable by clicking on the buttons at the top of the pane.
+<P>
+To delete one or more constraints, click on the appropriate checkbuttons in the <B>Delete</B> column and the press the Delete button, below.
+<img SRC="mc.gif" align=TEXTTOP>
+Due to the way GSAS implements these constraints, a parameter can be included 
+in only one constraint. Should one or more parameters be constrained twice, 
+an error message is shown as shown below.
+Note that the constraint number is displayed as red, for constraints that 
+have conflicts in the constraints editing pane (see above.)
+<img SRC="mcerr.gif" align=TEXTTOP>
+<P>
+<img SRC="mcedit.gif" align=LEFT>
+<img SRC="mcvar.gif" align=RIGHT>
+When the edit button for a constraint is pressed, the constraint is 
+opened for editing. Controls are available to select the phase, variable,
+multiplier and atom(s). Note that for atom selection, use of the control key 
+and the left mouse button allow individual atoms to be selected or deselected.
+Shift and the left mouse button allow ranges of atoms to be selected and the 
+right mouse button selects all atoms
+<A href="#mouseactions">(see Mouse Actions)</A>.
+<P>
+Note that it is inappropriate 
+to constrain different types of parameters together, for example X and Uiso.
+The left-most variable button is the "master" which 
+determines what variable are allowed in the
+other variable buttons. 
+<P>
+When the "New Constraint" button is pressed, a blank constraint editing
+window is opened. Note that any variable to the right may then be selected,
+including two special codes, Uxx and XYZU. XYZU creates four constraints, 
+requiring the shifts on x, y, z and Uiso to be the same for all the selected 
+atoms. Uxx does the same for the six anisotropic displacement parameters.
+These special codes are valuable for atoms that share a site.
+<P>
+Note that only 100 parameters may be included in a constraint, 
+with one exception. When shifts for Uiso for all atoms in a phase 
+are constrained, this counts as a single parameter. If more than 100 
+parameters are entered for a constraint, an error message is shown.
+Up to 2000 atomic constraints may be entered. 
+EXPGUI does not warn if you exceed this limit.
+</DL></DL>
+
+<P>
+<h3>A.7 Preferential Orientation Pane</h3></a>
+The Preferential Orientation Pane is used to control parameters related
+to fitting parameters using the March-Dollase formulation 
+for preferred orientation. In this model one or more axes are designated
+as directions [designated by (<i>hkl</i>)] where crystallites are over 
+(Ratio > 1) or underrepresented (Ratio < 1).
+The checkbox to the right of the Ratio value determines if it will 
+be refined.
+<img SRC="po1.gif" align=TEXTTOP>
+If more than one axis is present, one must define the relative fraction 
+of preferred orientation for each direction. These fractions are normalized, 
+so do not vary the fractions for all directions in a phase.
+<img SRC="po2.gif" align=TEXTTOP>
+If 
+<A href="#multiplehistogram">
+"Multiple Histogram Selection" mode</A> is set to any value other than 
+"Off", all terms are displayed for all selected histograms. 
+No attempt is made to group terms or flags.
+<P>
+Note that the other model for treating preferred orientation -- the orientation
+distribution function (spherical harmonics) is not yet implemented
+in EXPGUI and must be accessed from EXPEDT.
+
+<P>
+<h2>B. Shortcuts</h2></a>
+<a name="multiplehistogram">
+<h3>B.1 Multiple Histogram Selection</h3></a>
+<DL><DL>
+This mode allows parameters to be changed for groups of
+histograms. 
+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.
+<A href="#mouseactions">(see Mouse Actions)</A>.
+
+It does not make sense, however, to globally modify
+instrument-related parameters and flags for different 
+histogram types.
+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.
+<P>
+The setting for "Multiple Histogram Selection" mode is 
+selected using the "Multiple Hist. Selection" item on the 
+Options menu to create a submenu. Also on this submenu is an option
+"Group Phases Together" that controls how EXPGUI treats phases having
+the same profile type 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.
+<p>
+<a name="mouseactions">
+</DL></DL>
+<h3>B.2 Mouse Actions</h3></a>
+<DL><DL>
+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.
+</DL></DL>
+
+<h2>C. Menu Commands and Programs</h2>
 <p>
 GSAS programs are invoked either through use of the menu bar
@@ -61 +328 @@
 </center></B>
 
-<P>
-Different sections of the .EXP file can be edited by selecting different 
-panels or pages from the tabbed list. 
-<center><B>
-<br>The notebook panel tabs.
-<br><img SRC="panebar1.gif"  BORDER=3 >
-</center></B>
-<P>
-This documentation will describe the different actions that
-can be accomplished with the different panels and the 
-contents of the menus. Other documents contain:
-<a name="installation"></A>
-<A HREF="expgui_Win_readme.html">
-Installation notes for Windows</A>, 
-<A HREF="expgui_Unix_readme.html">
-Installation notes for UNIX</A> and
-<A HREF="expgui_cfg.html">
-Customization notes</A>.
-<hr>
-
-<h2>1. LS Controls panel</h2>
-<DL><DL>
-<p>The LS Controls panel shows information about the 
-current experiment, typically found in the EXPEDT "Least 
-Squares Controls" options. 
-<P>
-Note that the order that histograms appear in this 
-panel is determined by the "Sort histograms by" option in 
-the Options Menu.
-<img SRC="1.gif" align=TEXTTOP>
-</DL></DL>
-<P>
-<h2>2. Phase panel</h2> 
-<DL><DL>
-The phase panel is used to edit information
-about the phase or phases found in the experiment 
-file. The cell and atomic damping and refinement 
-flags can be changed here. Note that if a
-single atom is selected using the mouse, the information 
-for that atom can be edited. If a group of atoms is 
-selected
-<A href="#mouseactions">(see Mouse Actions)</A>
-the damping and refinement flags 
-for all the selected atom can be changed at one time.
-<P>
-If the EXPTOOL program 
-<A href="#installation">(see the installation instructions)</A>
-is installed, buttons for adding phases and atoms will 
-appear on this panel, as seen below. If the
-program is not properly installed, no errors occur, but the buttons
-do not appear.
-<P>
-Note that the order that atoms appear in this panel is 
-determined by the "Sort Atoms by" option in the Options
-Menu.
-<img SRC="2.gif" align=TEXTTOP>
-</DL></DL>
-
-<h2>3. Histogram panel</h2> 
-<DL><DL>
-The histogram panel is used to edit background
-and diffractometer constants for a histogram, as well as 
-set damping and refinement flags for these parameters.
-<P>
-If 
-<A href="#multiplehistogram">
-"Multiple Histogram Selection" mode</A> is set to "All", 
-this panel is disabled. For other settings of this mode, 
-groups of histograms can be selected and modified 
-collectively.
-<P>
-If the EXPTOOL program 
-<A href="#installation">(see the installation instructions)</A>
-is installed, a button for adding histograms will
-appear on the bottom right on this panel, as seen below. If the
-program is not properly installed, no errors occur, but the button
-does not appear.
-<P>
-Note that the order that histograms appear in this 
-panel is determined by the "Sort histograms by" option in 
-the Options Menu.
-<img SRC="3.gif" align=TEXTTOP>
-</DL></DL>
-
-<h2>4. Scaling panel</h2> 
-<DL><DL>
-The Scaling panel is used to edit the scale factor for a 
-histogram as well as the phase fractions for each phase
-present in that histogram. Damping and refinement flags
-can also be set here.
-<P>
-If 
-<A href="#multiplehistogram">
-"Multiple Histogram Selection" mode</A> is set to 
-any value other than "Off,"
-groups of histograms can be selected and modified 
-collectively.
-<P>
-Note that the order that histograms appear in this 
-panel is determined by the "Sort histograms by" option in 
-the Options Menu.
-<img SRC="4.gif" align=TEXTTOP>
-</DL></DL>
-
-<h2>5. Profile panel</h2> 
-<DL><DL>
-The Profile panel is used to edit the profile values for 
-each phase present in a histogram as well as set 
-the refinement flags and a damping value for each phase.
-<P>
-If 
-<A href="#multiplehistogram">
-"Multiple Histogram Selection" mode</A> is set to "All", 
-this panel is disabled. For other settings of this mode, 
-profile values and settings can be collectively
-modified for groups of histograms.
-<P>
-Note that the order that histograms appear in this 
-panel is determined by the "Sort histograms by" option in 
-the Options Menu.
-<img SRC="5.gif" align=TEXTTOP>
-</DL></DL>
-
-<h2>6. Constraints panel</h2>
-<DL><DL>
-GSAS offers two types of restraints that can be included in a model. 
-So called "soft constraints" or "restraints" penalize the fit if 
-aspects of a model (for example, bond lengths) differ from selected values.
-So called "hard constraints" reduce the actual number of 
-parameters in a model,
-by grouping parameters so that a single shift (possibly scaled) is 
-applied to each parameter in the group.
-The constraints panel is used to set these "hard constraints."
-At this time the only constraints that can be set in EXPGUI are on atomic
-parameters (others can be set in EXPEDT).
-<P>
-Note that these constraints are only applied to shifts, so that if two atoms 
-are constrained so that the shift on their occupancy is the same, but 
-the initial occupancies differ, the difference will be maintained as the
-values refine.
-<P>
-<H4>Atom Constraints</H3>
-The atom constraints editing page appears below. Note that constraints can 
-be listed sorted by constraint number, phase number, lowest atom number or
-variable by clicking on the buttons at the top of the page.
-<P>
-To delete one or more constraints, click on the appropriate checkbuttons in the <B>Delete</B> column and the press the Delete button, below.
-<img SRC="mc.gif" align=TEXTTOP>
-Due to the way GSAS implements these constraints, a parameter can be included 
-in only one constraint. Should one or more parameters be constrained twice, 
-an error message is shown as shown below.
-Note that the constraint number is displayed as red, for constraints that 
-have conflicts in the constraints editing page (see above.)
-<img SRC="mcerr.gif" align=TEXTTOP>
-<P>
-<img SRC="mcedit.gif" align=LEFT>
-<img SRC="mcvar.gif" align=RIGHT>
-When the edit button for a constraint is pressed, the constraint is 
-opened for editing. Controls are available to select the phase, variable,
-multiplier and atom(s). Note that for atom selection, use of the control key 
-and the left mouse button allow individual atoms to be selected or deselected.
-Shift and the left mouse button allow ranges of atoms to be selected and the 
-right mouse button selects all atoms
-<A href="#mouseactions">(see Mouse Actions)</A>.
-<P>
-Note that it is inappropriate 
-to constrain different types of parameters together, for example X and Uiso.
-The left-most variable button is the "master" which 
-determines what variable are allowed in the
-other variable buttons. 
-<P>
-When the "New Constraint" button is pressed, a blank constraint editing
-window is opened. Note that any variable to the right may then be selected,
-including two special codes, Uxx and XYZU. XYZU creates four constraints, 
-requiring the shifts on x, y, z and Uiso to be the same for all the selected 
-atoms. Uxx does the same for the six anisotropic displacement parameters.
-These special codes are valuable for atoms that share a site.
-<P>
-Note that only 100 parameters may be included in a constraint, 
-with one exception. When shifts for Uiso for all atoms in a phase 
-are constrained, this counts as a single parameter. If more than 100 
-parameters are entered for a constraint, an error message is shown.
-Up to 2000 atomic constraints may be entered. 
-EXPGUI does not warn if you exceed this limit.
-</DL></DL>
-
-<a name="multiplehistogram">
-<h2>7. Multiple Histogram Selection</h2></a>
-<DL><DL>
-This mode allows parameters to be changed for groups of
-histograms. 
-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.
-<A href="#mouseactions">(see Mouse Actions)</A>.
-
-It does not make sense, however, to globally modify
-instrument-related parameters and flags for different 
-histogram types.
-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 panels are disabled.
-<P>
-The setting for "Multiple Histogram Selection" mode is 
-selected using the "Multiple Hist. Selection" item on the 
-Options menu to create a submenu. Also on this submenu is an option
-"Group Phases Together" that controls how EXPGUI treats phases having
-the same profile type 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.
-<p>
-<a name="mouseactions">
-</DL></DL>
-<h2>8. Mouse Actions</h2></a>
-<DL><DL>
-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.
-</DL></DL>
-
-<h2>9. Menus</h2>
 A description of the EXPGUI menus follows along with a very 
 brief description of the function of each menu option.
 Note that an option may appear under more than one menu.
-<H3>9.1 File Menu</H3>
+<H3>C.1 File Menu</H3>
 <DL><DL>
 The options on the File menu as is the custom contains the commands 
@@ -314 +352 @@
 </DL></DL>
 
-<h3>9.2 Options Menu</h3>
+<h3>C.2 Options Menu</h3>
 <DL><DL>
 This menu contains options that determine how EXPGUI runs.
@@ -325 +363 @@
          shown in a separate window. When it is not set, the results are
         written in the .LST file.
-<DT>Sort atoms by<DD>   Determines the order that atoms are displayed on the "Phase" page
+<a name="sortatoms"></a><DT>Sort atoms by<DD>   Determines the order that atoms are displayed on the "Phase" pane
         Atoms may be displayed sorted by atom number, atom type, 
         or by x, y or z
 
-<DT>Sort histograms by<DD>Determines the order that histograms are displayed on the 
-        Histogram, Scaling and Profile pages
+<a name="sorthist"></a><DT>Sort histograms by<DD>Determines the order that histograms are displayed on the 
+        Histogram, Scaling and Profile panes
 
         Histograms may be sorted by histogram number, histogram type, 
@@ -345 +383 @@
         (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 pages are disabled.
+        the Histogram and Profile panes are disabled.
 <DT>Override backspace<DD>This option is available in UNIX only, as there are different
         ways that backspace can be implemented. When option is set 
@@ -358 +396 @@
 
 <DT>SaveOptions<DD>Save the current values for "Override backspace", 
-        "Sort atoms by", "Sort histograms by" and "archive EXP"
+        <a href="http:#sortatoms">"Sort atoms by"</a>, 
+        <a href="http:#sorthist">"Sort histograms by"</a> and "archive EXP"
         in file ~/.gsas_config (c:\.gsas_config on Windows).
 <DT>liveplot_options<DD>Used to set options for liveplot, 
@@ -366 +405 @@
 </DL></DL>
 
-<h3>9.3 Powder Menu</h3>
+<h3>C.3 Powder Menu</h3>
 <DL><DL>
 This menu contains links to GSAS programs used for powder diffraction
@@ -382 +421 @@
 </DL></DL>
 
-<h3>9.4 Single Crystal Menu</h3>
+<h3>C.4 Single Crystal Menu</h3>
 <DL><DL>
 This menu contains links to GSAS programs used for 
@@ -396 +435 @@
 </DL></DL>
 
-<h3>9.5 Graphics Menu</h3>
+<h3>C.5 Graphics Menu</h3>
 <DL><DL>
 This menu contains links to several GSAS and 
@@ -418 +457 @@
 </DL></DL>
 
-<h3>9.6 Results Menu</h3>
+<h3>C.6 Results Menu</h3>
 <DL><DL>
 This menu contains links to several GSAS and 
@@ -438 +477 @@
 </DL></DL>
 
-<h3>9.7 Calculations Menu</h3>
+<h3>C.7 Calculations Menu</h3>
 <DL><DL>
 This menu contains programs for useful crystallographic computations.
@@ -451 +490 @@
 </DL></DL>
 
-<h3>9.8 Import/Export Menu</h3>
+<h3>C.8 Import/Export Menu</h3>
 <DL><DL>
 This menu contains utilities for importing information into GSAS and
@@ -471 +510 @@
 </DL></DL>
 
-<h2>10. EXPGUI Utility Programs</h2></a>
+<h2>D. EXPGUI Utility Programs</h2></a>
 <DL><DL>
 <P><B>LSTVIEW</B>
@@ -536 +575 @@
 Przemek Klosowski</A>
 for convincing me to learn Tcl/Tk 
-and Jonathan Wasserman for starting this project.
-
+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).
+<P>
 <A Href="http://www.ncnr.nist.gov/programs/crystallography/software/gsas.html">
 GSAS</A>
@@ -545 +586 @@
 or kudos concerning GSAS should be sent to Robert B. Von Dreele at 
 <A HREF="MAILTO:vondreele@lanl.gov">vondreele@lanl.gov</A>
-<P>GSAS is Copyright, 1984-1997, The Regents of the University of California.
+EXPGUI is written by Brian H. Toby of the NIST Center for Neutron Research,
+<A HREF="MAILTO:Brian.Toby@NIST.GOV">Brian.Toby@NIST.GOV</A> 
+with help from Jonathan Wasserman.
+
+<P>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
@@ -555 +601 @@
 or implied, or assumes any liability or responsibility for the use of this
 software.
-<P>EXPGUI is written by Brian H. Toby of the NIST Center for Neutron Research,
-<A HREF="MAILTO:Brian.Toby@NIST.GOV">Brian.Toby@NIST.GOV</A> 
-with help from Jonathan Wasserman.
-
-<P>EXPGUI is not subject to copyright. Have fun with it.
+
+<P>EXPGUI is not subject to copyright. Have fun with it. Modify it. Write 
+new sections and make them available to the reset of the world. 
 
 <p>Neither the U.S. Government nor any author makes any warranty,