Skip to content

Interactive Data Lanuguage (IDL)

IDL, short for Interactive Data Language, is a programming language used for data analysis developed by Exelis Visual Information Solutions. CHPC maintains IDL licenses for the Department of Atmospheric Sciences and for the Department of Astrophysics. Note that only the Atmospheric Sciences licenses are renewed annually so they are entitled to use the latest version. The Department of Astrophysics users should use IDL version 8.4 or lower.

IDL is available on all CHPC clusters, supported departmental Linux servers and for local installation on desktops upon request.

For Linux based desktops, and for the compute clusters, CHPC maintains IDL in the common sys branch which is mounted on all CHPC maintained Linux machines. Different IDL versions ares located in /uufs/

In order to use IDL, the terminal environment has to be set up properly by loading the IDL module:

module load idl

To find out what versions of IDL are available, one can use the module spider search:

module spider idl

If users want to add a new path for IDL to search for routines, make sure the IDL_DEFAULT is included as well, otherwise the routines shipped with IDL will not work. Also, note that adding a plus sign (+) before the path name tells IDL to search the current directory and its subdirectories for the given routine name. Finally, we have seen sometimes that the user home directory denoted with ~ (e.g. ~u0123456) is not expanded correctly in the PATH variables. Use the full path instead (e.g. /uufs/

To add to IDL_PATH user directory /uufs/ and all its subdirectories, do the following:

setenv IDL_PATH "+/uufs/<IDL_DEFAULT>"

For users running IDL on Linux machines (e.g. the meteo nodes) by logging into them from their Windows desktops, if you use Xming for X11 forwarding, please, create a new alias for IDL as:

alias idl 'idl -IDL_GR_X_RENDERER 1'

This is best put to your .tcshrc or your .aliases file. It will tell IDL to use the computer's processor to handle graphics instead of the
graphics card and avoid some errors IDL may show otherwise.

Last Updated: 1/30/24