source: trunk/doc/expgui3.html @ 594

Last change on this file since 594 was 569, checked in by toby, 12 years ago

# on 2002/04/12 19:49:04, toby did:
remove identification stuff

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1<html>
2<head>
3   <title>EXPGUI</title>
4   <meta name="keywords" content="crystallography, Rietveld, diffraction,
5   GSAS, EXPGUI">
6</HEAD>
7<style>
8A:link {text-decoration:none}
9A:vlink {text-decoration:none}
10</style>
11
12<BODY BGCOLOR="#FFFFFF"
13      topmargin="0" leftmargin="0" marginwidth="0" marginheight="0" 
14      text="#000000" link="#0033ff" vlink="#0033ff" alink="#0033ff">
15
16<?
17   include("/var/www/include/navigation.inc");
18   include("/var/www/include/utility.inc");
19?>
20<blockquote><font face="arial, helvetica, sans-serif">
21
22<TABLE BORDER BGCOLOR="#FFFF40" ALIGN=RIGHT>
23<TR><TH><A  Href="expgui.html">EXPGUI top</A> 
24</TH><TH><A Href="expgui4.html">Next page</A>
25</TH><TH><A Href="expgui2.html">Previous page</A>
26</TH></TR></TABLE><BR CLEAR=ALL>
27
28<center><h1>
29<HR noshade width="75%" size="2" align="center">
30EXPGUI, part 3
31<HR noshade width="75%" size="2" align="center">
32</h1></center>
33<h3>A.3 Histogram pane</h3> 
34<DL><DL>
35The histogram pane is used to edit background
36and diffractometer constants for a histogram, as well as
37set damping and refinement flags for these parameters.
38<P>
39If
40<A href="expgui.html#multiplehistogram">
41"Multiple Histogram Selection" mode</A> is set to "All",
42this pane is disabled. For other settings of this mode,
43groups of histograms can be selected and modified
44collectively.
45<P>
46If the EXPTOOL program
47<A href="expgui.html#installation">(see the installation instructions)</A>
48is installed, a button for adding histograms will
49appear on the bottom right on this pane, as seen below. If the
50program is not properly installed, no errors occur, but the button
51does not appear.
52<P>
53Note that the order that histograms appear in this
54pane is determined by the <a href="expguic.html#sorthist">"Sort histograms by"</a> option in
55the Options Menu.
56</DL></DL>
57</blockquote>
58<img SRC="3.gif" align=TEXTTOP alt="EXPGUI Screen snapshot">
59<blockquote>
60<br clear=all>
61
62<a name="EditBackground"></a>
63<h3>A.3.1 Editing background</h3> 
64<DL><DL>
65<img SRC="3b1.gif" align=TEXTOP alt="EXPGUI Screen snapshot">
66When the button labeled "Edit Background", (or "Globally Edit Background"
67or in the case where <A href="expgui.html#multiplehistogram">
68"Multiple Histogram Selection" mode</A> is set to a single histogram type)
69is pressed, a window such as the one
70to the left is displayed. In the case where background coefficients
71are being edited for more than one histogram
72(<A href="expgui.html#multiplehistogram">
73"Multiple Histogram Selection" mode</A> must be
74set to a single histogram type) the entry boxes will appear blank
75and only those terms that are filled in will be changed when the "Set"
76button is pressed.
77This option is mostly useful when changing the background function or the
78number of terms for several histograms at a single time.
79Note that no changes are made until the "Set"
80button is pressed.
81<P>
82<IMG SRC="new.gif" HEIGHT=13 WIDTH=36 alt="New!">
83The "Fit Background Graphically" button is displayed only when a single
84histogram is selected for background editing. When this button is
85pressed, the <A HREF="liveplot.html#bkgedit">BKGEDIT</A> program is
86called to fit a background function to user-input fixed background points.
87See the <A HREF="liveplot.html#bkgedit">BKGEDIT documentation</A> for more
88information.
89</DL></DL>
90<br clear=all>
91
92<a name="EditAbsorption"></a>
93<h3>A.3.2 Editing absorption/reflectivity
94<IMG SRC="new.gif" HEIGHT=13 WIDTH=36 alt="New!">
95</h3> 
96<DL><DL>
97<img SRC="3h.gif" align=RIGHT alt="EXPGUI Screen snapshot">
98The refinement flag and damping factor for correction for absorption
99effects (or for flat-plate samples, reflectivity corrections) can be
100seen in a box near the bottom of the pane.
101The terms and the type of correction used
102are set using the "Edit Abs./Refl." button in this box. Pressing this
103button creates a window, shown to the right. A message is shown in the
104bottom of the window summarizing information about the selected correction.
105<P>
106<a name="AbsorptionSanity"></a>
107Please note, each correction is only appropriate for certain types of data
108and frequently the correction must be fixed rather than refined. It is
109wise to read the "Powder absorption factor" section of the GSAS manual
110(p 138-140 in 1/19/01 edition) before using this correction.
111Since some combinations of data types and correction types are unlikely --
112but not impossible
113(for example, a cylindical absorption correction and K-alpha1,2 radiation)
114EXPGUI will generate a warning message, such as the one below,
115but not all inappropriate actions can be prevented.
116The user must ultimately understand the role of the correction
117and the nature of the experiment to decide what is appropriate.
118<br clear=all>
119<img SRC="3h1.gif" align=TEXTTOP alt="EXPGUI Screen snapshot">
120<br clear=all>
121</DL></DL>
122<br clear=all>
123
124<a name="EditParm"></a>
125<h3>A.3.3 Global Editing of Parameters</h3> 
126<DL><DL>
127It is possible to access parameters and settings for more than one histogram
128at a time when a multiple selection of a specific histogram type
129is allowed
130(see
131<A href="expgui.html#multiplehistogram">
132"Multiple Histogram Selection" mode</A>).
133In this mode, the histogram pane
134appears slightly differently, as is shown below.
135</DL></DL>
136</blockquote>
137<img SRC="3c.gif" align=TEXTTOP alt="EXPGUI Screen snapshot">
138<blockquote>
139<br clear=all>
140<DL><DL>
141<img SRC="3d.gif" align=LEFT alt="EXPGUI Screen snapshot">
142Pressing a refinement flag checkbox will set all
143selected histogram refinement flags either off or on.
144Pressing a "Globally Edit..." button, will allow a parameter to be set.
145For example, the window to the left shows how
146a diffractometer constant can be
147edited for more than one histogram
148<P>
149A similar window is also used to globally set the
150<A href="expgui4.html">Phase Fraction</A> in
151<A href="expgui.html#multiplehistogram">
152"Multiple Histogram Selection"</A> mode.
153<br clear=all>
154
155</DL></DL>
156
157<a name="AddHist"></a>
158<h3>A.3.4 Entering New Diffractograms</h3> 
159<DL><DL>
160<img SRC="3e.gif" align=RIGHT alt="EXPGUI Screen snapshot">
161Pressing the "Add New Histogram" button creates the dialog
162to the left. This can be used to select diffraction data to be used
163in the refinement, or if the "dummy histogram" boxed is selected,
164a set of diffraction data can be simulated.
165<P>
166In the case where diffraction data will be input,
167a data file and an instrument parameter file must be
168selected using the "Select File" buttons. The limit for reflection
169generation (maximum energy or two-theta, or minimum d-space or TOF)
170must be entered, as well as the units.
171If more than one bank is defined, either in the data file or in the
172instrument parameter file, the bank must be selected as well.
173Note that the data range can be edited at a later time using the
174<a href="excledt.html">EXCLEDT</a> utility.
175<P>
176To view a plot of a data file, so that the range of the data
177may be viewed, the RAWPLOT program may be invoked using the "Run RAWPLOT"
178button. Note that EXPGUI cannot communicate the names
179of the data and instrument parameter files to RAWPLOT, so they must be
180reentered.
181<P>
182<br clear=all>
183<img SRC="3e1.gif" align=RIGHT alt="EXPGUI Screen snapshot">
184When the dummy histogram option is selected, diffraction data can
185be simulated based a set of experimental constants
186described in an instrument parameter file.
187Note that most of these instrumental parameters,
188such as wavelength or DIFC can be edited on this pane or
189on the <A HREF="expgui5.html">profile</A> pane
190(the simulated pattern is also affected by constants on the
191<A HREF="expgui4.html">scaling</A> pane.)
192The 2-theta/energy/TOF
193range to be used for the computation, as well as the step size,
194must be entered before pressing the "Add" button.
195Note that once the histogram is added, this range and step size
196cannot be edited within EXPGUI at present. However,
197EXPEDT can be used to change these values.
198<br clear=all>
199<P>
200<a name="AddHistErr"></a>
201<img SRC="3e2.gif" align=LEFT alt="EXPGUI Screen snapshot">
202If errors are detected in the input, an error message is displayed
203detailing where the errors are found. Otherwise, the EXPTOOL program is run
204and the output is optionally displayed
205(See <a href="expguic.html#exptoolout">Show EXPTOOL output</a>).
206</DL></DL>
207<br clear=all>
208<P>
209<h3>A.3.5 Editing the Data Range & Excluded Regions</h3> 
210<DL><DL>
211The button at the bottom of the pane, labeled
212"Set Data Limits & Excluded Regions" invokes
213the <a href="excledt.html">EXCLEDT</a> utility, which is used to
214modify the lower and upper data limits and can be used to add or delete
215excluded regions.
216</DL></DL>
217
218<h3>A.3.6 Setting Histogram Flags</h3> 
219<DL><DL>
220<img SRC="3f.gif" align=RIGHT alt="EXPGUI Screen snapshot">
221The button at the bottom of the pane, labeled "Set Histogram Use Flags" invokes
222a menu where the "Use"/"Do not use" flag for powder histogram can be set.
223When this flag is turned off, the histogram is ignored for
224subsequent computations, effectively removing from the experiment.
225<P>
226When these "Use" flags are changed, it is necessary to run POWPREF,
227to propogate the changes. After the "Save" button is pressed, a prompt such
228as the example below, is generated to run POWPREF. Note that GENLES may
229fail if POWPREF is not run after changing these flags.
230<br clear=all>
231<P>
232<img SRC="3g.gif" align=TEXTTOP alt="EXPGUI Screen snapshot">
233<br clear=all>
234</DL></DL>
235
236<h3>A.3.7 Setting Phase Flags</h3> 
237<DL><DL>
238If there is more than one phase present in the refinement,
239an extra box appears at the top of the pane to allow phase flags
240to be selected. This allows a phase to be used in some histograms
241but not in others. It also offers a simple way to effectively "delete" a
242phase by removing it from all histograms. Be sure to rerun POWPREF after
243changing the phase flags.
244</DL></DL>
245</blockquote>
246<img SRC="3a.gif" align=TEXTTOP alt="EXPGUI Screen snapshot">
247<blockquote>
248<br clear=all>
249<hr>
250<TABLE BORDER BGCOLOR="#FFFF40" ALIGN=RIGHT>
251<TR><TH><A  Href="expgui.html">EXPGUI top</A> 
252</TH><TH><A Href="expgui4.html">Next page</A>
253</TH><TH><A Href="expgui2.html">Previous page</A>
254</TH></TR></TABLE>
255
256<P><font size=-1><A HREF="MAILTO:crystal@NIST.gov?subject=WWW page <?=$PHP_SELF?>">Comments, corrections or questions: crystal@NIST.gov</A></font><BR>
257<font size=-1><? lastmod(); ?> </font>
258<br>$Revision: 569 $ $Date: 2009-12-04 23:08:22 +0000 (Fri, 04 Dec 2009) $
259</blockquote>
260</body>
261</html>
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