source: trunk/tutorial1/nickel3.html @ 195

Last change on this file since 195 was 185, checked in by toby, 12 years ago

# on 2000/06/01 16:07:21, toby did:
correct typos

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  • Property rcs:date set to 2000/06/01 16:07:21
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  • Property rcs:rev set to 1.2
  • Property rcs:state set to Exp
  • Property svn:keywords set to Author Date Revision Id
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1<html>
2<head>
3   <META NAME="Author" CONTENT="Brian H. Toby">
4   <title>EXPGUI Tutorial #3</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 3)</H1>
25</CENTER>
26<H1>
273. Add data (histograms) to the Experiment
28</H1>
29
30The next step in the tutorial is to add data. Note that
31GSAS uses the term
32histogram to refer to a powder diffraction data set.
33To add data, switch to the Histogram in EXPGUI pane and press the
34"Add New Histogram" button in the lower right.
35<img src="addhs1.gif" ALIGN=LEFT>
36This brings up the "add new histogram" dialog, to the left.
37Press on the upper "Select File" button for a dialog box to select
38a data file.
39
40<BR clear=left>
41<img src="addhs2.gif" ALIGN=LEFT>
42Select the appropriate file, in this case nickel.raw and press
43the "Open" button.
44
45At this stage, different things can happen.
46If the file is not correctly formatted,
47<A HREF="nickelnotes.html#reformat">a dialog will offer
48to convert the file to the correct format.</a>
49Also, in some cases, the data file specifies the name of the instrument
50parameter file. If so, that name will be loaded into the "Instrument
51Parameter file" box. If not, as in this case, the file must be selected
52by pressing the lower "Select File" button which creates a
53dialog box to select an instrument parameter file, similar
54to the one above.
55
56<BR clear=left>
57<img src="addhs3.gif" ALIGN=LEFT>
58After the appropriate instrument parameter file is located and selected,
59one must select the bank of data (if more than one) and the bank of the
60instrument parameters (if more than one) using the bank checkbuttons.
61Finally one must enter either the minimum d-space or
62maximum time-of-flight or two-theta to be used from the data (note that
63this value can be changed later if need be from EXPEDT). A
64good way to do this is to use
65<A HREF="nickelnotes.html#rawplot">RAWPLOT</A>
66to look at the data. This is done
67by pressing the "Run RAWPLOT" button at the
68lower right <A HREF="nickelnotes.html#rawplot">(example).</A>
69
70
71When all input is complete, press Add to run program EXPTOOL and read the
72data into the .EXP file.
73
74<BR clear=left>
75<img src="addhs4.gif" ALIGN=LEFT>
76The results from the EXPTOOL are shown in a separate box, so
77that errors can be noted.
78
79<BR clear=left>
80<img src="addhs5.gif" ALIGN=LEFT>
81The above procedure is then repeated for the third bank of data, but this
82time the maximum time-of-flight is changed to 1.5.
83<P>After Add is pressed, the EXPTOOL results are
84displayed and then the histogram panel is
85updated so that the diffraction parameters
86for each of the two histograms can be examined
87(see below).
88<BR clear=left>
89<img src="addhs6.gif">
90<BR clear=left>
91There is one deviation in the above
92compared to the tutorial in the GSAS manual.
93In that tutorial the
94data compression factor is set to 2 for the
95first histogram, averaging pairs
96of points to speed up
97the computations. This cannot be done from EXPGUI.
98If desired, it can be done using EXPEDT, but for
99most modern computers this tutorial will still run
100in seconds with no compression.
101
102<P><BR>(.EXP Snapshot:
103<A HREF="ftp://ftp.ncnr.nist.gov/pub/cryst/gsas/tutorials/nickel3.exp">
104nickel3.exp
105</A>)
106
107<BR clear=left><HR>
108Previous step: <A HREF="nickel2.html">
109Add a phase to the Experiment</A>
110<BR>
111Next step: <A HREF="nickel4.html">
112 Change a profile parameter</A>
113
114<BR clear=left>
115<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>)
116<BR clear=left>
117$Revision: 185 $ $Date: 2009-12-04 23:01:49 +0000 (Fri, 04 Dec 2009) $
118</body>
119</html>
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