School of Physics & Astronomy
School of Physics and Astronomy Wiki

### User Tools

computing:department:unix:software:idl

# IDL on Physics linux systems

IDL is supported on the linux cluster primarily for specific research groups in Astronomy and Cosmology. A few licenses are also provided by Physics and Astronomy for general use.

To use IDL, you first need to load the software module:

module load idl

After that, for a command line interface, type

idl

or for IDL's development environment, type

idlde

For interactive help, type

idlhelp

## The IDL Astronomy User's Library

<note>possibly outdated info?</note>

The IDL Astronomy Users Library is a central repository for low-level astronomy software written in the commercial language IDL. More info at http://idlastro.gsfc.nasa.gov/.

In order to use the network copy of this software, you must modify the IDL_PATH environment path.

For csh:

setenv IDL_PATH "<IDL_DEFAULT>:/local/astro/idl_astro/pro"

for bash:

export IDL_PATH="<IDL_DEFAULT>:/local/astro/idl_astro/pro"

## Running multiple copies of IDL on the same machine

This hint was taken from Princeton Astronomy department: IDL hands out licenses based on hostname+username+display. If all three of those are equal, you can start as many sessions as you want and only consume one license. The modern habit of letting ssh create X tunnels causes the display name to be different for each ssh connection, even if several connections come from a single host. There are several ways of making your DISPLAY name the same for all such connections. The simplest is to note which your first one is (echo \$DISPLAY), and set DISPLAY on other connections to that. Or for a console-only IDL session, simply unset DISPLAY completely.