GUI Windows

Known Problems


This document describes the EPICS_SSCAN_DISPLAY graphical user interface for reading and displaying EPICS scan data from MDA files collected with the EPICS sscan record and saveData. This class basically implements a GUI interface to the underlying EPICS_SSCAN class. It displays data using the very powerful IDL iTools graphical system, as well as in ASCII format. The iTools permit interactive manipulation of the graphical display, and can be used to produce publication quality plots.

This package can be used instead of the older scanSee program for displaying MDA files. Because it uses IDL iTools, rather than IDL direct graphics, it provides much more sophisticated graphics than scanSee, with much less code.

The EPICS_SSCAN_DISPLAY software is available in both source code form and as an IDL save file (mda_display.sav) in a compressed tar file.

By using the mda_display.sav file the package can be run for free with the IDL Virtual Machine.

Note that the display routines require the iTools system in IDL, which is only available in IDL 6.0 and newer releases. The current mda_display.sav file was built with IDL 6.3, and users should download that version of the IDL Virtual Machine.

GUI Windows

The top level window is show below. This window can be obtained with the following IDL command:
IDL> mda_display
When using the IDL Virtual Machine this display will appear when opening the file mda_display.sav.

Hopefully the GUI is quite self-explanatory. The "Read MDA file" button is used to select an MDA file to read. If there are files with sequence numbers before and after the selected file in that directory, then the "Previous file" and "Next file" buttons will be available. When an MDA file is read in, a new window like the following is created, which contains all of the information about the scan.

This window makes extensive use of tabs to display a large amount of information in a reasonable amount of screen real estate. The top level tab is used to select the scan in the MDA file. In the example shown above there are 3 scans, 2xfm:scan2, 2xfm:scan1, and 2xfm:scanh. For each scan there are then 3 tabs displayed: "Positioners", "Detectors", and "Display range". The detectors are displayed on multiple tabs, each containing the information for 10 detectors. For each positioner and detector, descriptive information (EPICS PV name, units, description, and minimum and maximum value) is displayed. Each positioner or detector can be selected with a check box to be included in the display. Once the desired positioners and detectors are selected the "Display with iTools" button can be used to produce an iTools display. In the example shown here, this results in the following display.

This image was manipulated using the iTools display to increase the zoom to 400% for each image and to modify the color tables.

The "Display range" tab can be used to limit the range of data displayed for each dimension in a scan. For example:

In the example shown above the first dimension was changed from "Points" to "Cut", and Start and Stop for that dimension were changed from 1,61, to 31,31. This results in a 1-D data set. Pushing the "Display with iTools" button after making this change results in the following display of column 31 for each of the 4 detectors.

For each dimension one can select the Start and Stop index to be displayed. The "Mode" for each dimension can have the following values:

In addition to displaying scan data with the iTools, it is possible to display the selected scan, positioners, and detectors in ASCII with the "Display in column format" button. In this example this results in the following display.

This window can be edited (to delete unwanted rows, for example), and saved to a file. It is a convenient format for reading into other programs, such as spreadsheets.

On the main display window there are several Display Options.

On the main display window there are options for displaying the overall MDA file in ASCII. This display is mainly intended to be humanly readable. The "Display in column format" button on the scan window is better suited for producing output to be read by other programs.

The output when pressing "Display as ASCII" button is as follows.

Known Problems

Suggestions and Comments to:
Mark Rivers : (rivers@cars.uchicago.edu)
Last modified: October 17, 2006