View Data

Visualize Data Using IDL

You will be using the IDL visualization software package included with the FLASH code. This assumes that IDL is installed on your machine, and that you have access to an IDL license. Please come talk to Sean, if this is not the case. I think, you will also have to compile some of the HDF5 wrapper routines (according to the FLASH user's manual), so I will add more on this later.

Step-by-Step:

  1. First, you'll need to copy the FLASH IDL routines to somewhere that can be seen by the machine on which you run IDL:

    1. Make an IDL library directory wherever you want (e.g., $HOME/lib/).

    2. In that directory, get a copy of the FLASH code (e.g., using the cvs command given here). The FLASH IDL routines are in the FLASH2.2/tools/fidlr2/ directory.

  2. Tell IDL where to find the FLASH IDL routines:

    1. Put the following lines in your .cshrc (or equivalent) file:

      setenv XFLASH_DIR $HOME/lib/FLASH2.2/tools/fidlr2

      setenv IDL_STARTUP $HOME/idldir/idl.startup

      The XFLASH_DIR environment variable needs to be set for the xflash routine to run properly.

      The IDL_STARTUP environment variable tells IDL to read the batch file called "$HOME/idldir/idl.startup" each time IDL is run. Replace "idldir" with whatever you want.

      Be sure to source the .cshrc file when you have finished.

    2. Create a file called "idl.startup" in the $HOME/idldir/ (or whatever you put above) directory, and add the following line to it:

      !path = !path + ':$HOME/lib/FLASH2.2/tools/fidlr2'

      This actually tells IDL where the routines are.

  3. Start IDL.

    idl

  4. Run the xflash routine:

    IDL> xflash

    This should pop up a window that looks something like this:

  5. Select "Open prototype..." in the file menu, and find a data file that you want to view.

  6. Click on "Plot" at the bottom of the window, and you should get an IDL window that looks something like this:

    Play with the buttons in the xflash window to vary the output (e.g., I pressed the "show blocks" button for the image shown above).

Additional Information:

IDL is easy to download and install from the RSI homepage . Without a license, you can run IDL seven minutes at a time (with some limited functionality). We'll eventually need to sort out the licensing issue.

Learn more about hierarchical data format (HDF) libraries at the HDF Group homepage.

The FLASH user's guide and FAQ describe the viewing of FLASH data with IDL in greater detail.

For IDL help, type "?" and enter at the IDL prompt.

Also, I (Sean) am willing and usually able to help with IDL related questions.

Go back to practical FLASH notes page .