Changes between Version 7 and Version 8 of DemoIntegrateTilted


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Timestamp:
Jul 28, 2011 8:57:38 AM (11 years ago)
Author:
toby
Comment:

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  • DemoIntegrateTilted

    v7 v8  
    11= Calibration of an area detector in GSAS-II =
    22
    3 ''In this demo, data collected with a GE(?) area detector, intentionally tilted at 45 degrees, are used. Note that menu entries are listed as Help/About GSAS-II, which refers to the name of the menu (here "Help") and the name of the entry in the menu (here "About GSAS-II").''
     3''In this demo, data collected with a GE(?) area detector, intentionally tilted at 45 degrees, are used. Note that menu entries are listed below as Help/About GSAS-II, which lists first the name of the menu (here "Help") and second the name of the entry in the menu (here "About GSAS-II").''
    44
    5 Step 1: download the data file from one of these links
     5=== Step 1: download the data file  ===
     6Download the sample data file from one of these links:
    67    https://subversion.xor.aps.anl.gov/trac/pyGSAS/browser/Examples/images/tilt-11ID/La_hex_%2B45deg-00015.tif?format=raw
    78    or https://subversion.xor.aps.anl.gov/pyGSAS/Examples/images/tilt-11ID/La_hex_+45deg-00015.tif
    89
    9 Step 2: start GSAS-II in the directory where you have placed that file. This is done in different ways depending on your OS and how GSAS-II is installed.
     10=== Step 2: Start GSAS-II ===
    1011
    11 {{{
     12 This is done in different ways, depending on your OS and how GSAS-II is installed.
     13
     14   {{{
    1215apsvisit24d:demo1 toby$ python ~/software/work/GSASII/GSASII.py
    1316Available python module versions for GSASII:
     
    2023Max threads  1
    2124}}}
    22 You should see two windows, both empty. One is labeled GSASII Plots, the other GSAS-II data tree. On Linux and Windows a menu bar appears on the latter window; on a Mac the menu is in the system menu bar location (usually at the screen top).
    2325
    24 Step 3: read in the data file.
     26 The GSAS-II program has now been started and an empty project file is created. The project file contains all data and results related to the project you are working on. (Exception: image files are not stored in the project; to save space only the file name is saved.)
     27You should see two windows, both empty. One, in the upper left, is labeled GSASII Plots, the other, in the upper right, is labeled GSAS-II data tree. On Linux and Windows a menu bar appears on the latter data tree window; on a Mac the menu is in the system menu bar location (usually at the screen top).
    2528
    26  Use the Data/Read image data menu item
     29=== Step 3: read in the data file ===
     30
     31 Use the Data/Read image data menu item to read the data file into the current GSAS-II project.
    2732 ([https://subversion.xor.aps.anl.gov/trac/pyGSAS/attachment/wiki/DemoIntegrateTilted/d1m1.png view]).
    2833 Select the La_hex_+45deg-00015.tif data file and press Open.
     
    3540 ([https://subversion.xor.aps.anl.gov/trac/pyGSAS/attachment/wiki/DemoIntegrateTilted/d1w3.png view]). 
    3641
    37 Step 4: Edit image parameters
     42=== Step 4: Edit image parameters ===
    3843
    3944 Note that, alas, very few image formats allow for storage of important metadata about the image, so this information needs to be added manually. In this case set the '''wavelength to 0.10798'''. It is also helpful to change the display of the image so that it is easier to see the diffraction rings. Lowering the maximum intensity to 10,000 to 20,000 counts will help (note that this can be done by moving the slider, or by typing a value in the box and then clicking on another control). You may also wish to select another color scheme using the color bar selector.
     
    4146 Alternately, the view of the image can be enhanced by displaying it on a logarithmic scale. Click on the window and press the upper or lowercase "L" key to toggle logarithmic plotting, or use the keypress selector button at the lower left of this window.
    4247
    43 Step 5: Calibrate
     48=== Step 5: Calibrate ===
    4449
    4550 First:
     
    6974 ([https://subversion.xor.aps.anl.gov/trac/pyGSAS/attachment/wiki/DemoIntegrateTilted/d1w8.jpg view]).
    7075 When this is done, it becomes clear that the points selected for the outermost ring are scattered between that and the next ring. This can be repaired by using the Image Operations/Clear Calibration menu item, lowering the area the program uses for searching for points by changing the "pixel search range" to 10 and then repeating the calibration steps (selecting points again on the first ring and then using the right mouse button)
     76 ([https://subversion.xor.aps.anl.gov/trac/pyGSAS/attachment/wiki/DemoIntegrateTilted/d1w10.jpg view]).
     77 This produces very slightly better calibration constants
    7178 ([https://subversion.xor.aps.anl.gov/trac/pyGSAS/attachment/wiki/DemoIntegrateTilted/d1w9.jpg view]).
    72  This produces very slightly better calibration constants
    73  ([https://subversion.xor.aps.anl.gov/trac/pyGSAS/attachment/wiki/DemoIntegrateTilted/d1w10.jpg view]).
     79
     80 Assuming that these calibration results will be applied to other images in the same GSAS-II project, click on "Use as default for all images." To save the project, including the now-derived calibration information, use the File/Save Project menu item associated with the data tree window.
     81
     82== Next step: [IntegrateData Integrate the Data]