source: trunk/tutorial1/nickel5.html @ 474

Last change on this file since 474 was 208, checked in by toby, 12 years ago

# on 2000/06/09 03:57:42, toby did:
incorporate many useful comments by Egbert Keller

  • Property rcs:author set to toby
  • Property rcs:date set to 2000/06/09 03:57:42
  • Property rcs:lines set to +22 -12
  • Property rcs:rev set to 1.2
  • Property rcs:state set to Exp
  • Property svn:keywords set to Author Date Revision Id
File size: 3.2 KB
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[161]1<html>
2<head>
3   <META NAME="Author" CONTENT="Brian H. Toby">
4   <title>EXPGUI Tutorial #5</title>
5</head>
6<BODY BGCOLOR="#FFFFFF">
7
8<A HREF=http://www.ncnr.nist.gov>
9<IMG SRC="http://www.ncnr.nist.gov/images/ncnrtrans.gif" 
10alt="Link to NIST Center for Neutron Research home page"
11ALIGN=RIGHT></A>
12<A HREF=http://www.nist.gov>
13<IMG SRC="http://www.ncnr.nist.gov/images/webidblue_2lineright.gif" 
14alt="Link to National Institute of Standards & Technology home page"
15ALIGN=LEFT></A>
16<CENTER>
17<A Href="http://www.ncnr.nist.gov/programs/crystallography/software/tclpkgs.html">
18<IMG SRC="tcltklogo100.gif" 
19alt="Link to Tcl/Tk information">
20</CENTER></A>
21<hr>
22
23<CENTER>
24<H1>GSAS Nickel example using EXPGUI (part 5)</H1>
25</CENTER>
26<H1>
275. Run POWPREF
28</H1>
29<img src="powpref2.gif" align=left>
30Before a least-squares refinement can be run, the POWPREF program
31must be run. This program assigns the reflections that are associated with
32each data point in each histogram. For this reason, POWPREF should
33be rerun if the lattice constants change, if peak widths or
34asymmetry parameters change or if you change the range of data
35that you are using in any histogram.
36<P>
37POWPREF can be run in one of three ways. It can be invoked from the
38menu item in the Powder menu (see to the left), or as a button in
39the button bar (see below) or by pressing the Alt-P key combination.
40<BR clear=left><P>
41<img src="powpref1.gif">
42<BR>
43<P>
44<img src="powpref3.gif">
45<BR>
46<img src="powpref4.gif" align=left>
47Once POWPREF is started, a window is opened to watch the program
48progress, as is shown above.
49<P>
[208]50The exact behavior of the window after the run completes is somewhat
51system-dependent. In Windows-95 and UNIX you must press the "Enter" or
52"Return" key for the run to complete, but in Windows-NT this is not
53the case. For both versions of Windows, you may or may not need to
54close the window manually once the run is complete, depending on your
55system's settings.
56<P>
57Every time that EXPGUI detects that a change has been made in the .EXP file
58by another program (in this case by POWPREF) this message appears to offer
59to choices: to continue using the previously read file or to reload the
60changed file. If you press the "Continue editing" button, EXPGUI will
61ignore the changes in the .EXP file made by POWPREF, but if you press
62the "Load new", these changes are read and accepted.
63<P>
64In this case press
65"Load new" to use the results of POWPREF. However if a program
66makes changes to the .EXP file that you do not like
67(this is most common with GENLES, when a refinement diverges)
68you can reject the changes by pressing "Continue editing." When the
69.EXP file is later changes and saved, it will overwrite the results in
70the rejected run.
[161]71
72<P><BR>(.EXP Snapshot:
73<A HREF="ftp://ftp.ncnr.nist.gov/pub/cryst/gsas/tutorials/nickel5.exp">
74nickel5.exp
75</A>)
76
77<BR clear=left><HR>
78Previous step: <A HREF="nickel4.html">
79Change a profile parameter
80</A>
81<BR>
82Next step: <A HREF="nickel6.html">
83Plot data using POWPLOT or LIVEPLOT</A>
84
85<BR clear=left>
86<HR><p><a href="http://www.ncnr.nist.gov/staff/toby/">Brian Toby</a> (<a href="mailto:brian.toby@nist.gov">Brian.Toby@NIST.GOV</a>)
87<BR clear=left>
88$Revision: 208 $ $Date: 2009-12-04 23:02:12 +0000 (Fri, 04 Dec 2009) $
89</body>
90</html>
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