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IDL stands for Interactive Data Language. It is a graphics package. It can be used interactively, or run in batch mode for data analysis.

More information:

How to use 

Login to Gadi with X11 (X-Windows) forwarding. Add the -Y option for Linux/Mac/Unix to your SSH command to request SSH to forward the X11 connection to your local computer. For Windows, we recommend to use MobaXterm ( as it automatically uses X11 forwarding.

For more information of MobaXterm and X-forwarding, please see our connecting to Gadi page

You can check the versions installed in Gadi with a module query:

$ module avail idl

We normally recommend using the latest version available and always recommend to specify the version number with the module command:

$ module load idl/8.8

For more details on using modules see our software applications guide.

Please make sure the number of process is consistent with the number of ncpus in your job request. By default, IDL will use all the CPUs on the node. You should specify TPOOL_NTHREADS to be $PBS_NCPUS in your environment.

In order to run IDL in an interactive way, Start an interactive PBS job with the following command on Gadi. It requests 1 CPU, 2 GiB memory, and 8 GiB local disk on a compute node on Gadi from the normal queue for 30 minutes against the project a00. It also requests the system to enter the working directory once the job is started. To change the number of CPU cores, memory, or jobfs required, simply modify the appropriate PBS resource requests in the qsub command below according to the information available in our queue structure guide. 

Note that if your application does not work in parallel, setting the number of CPU cores to 1 and changing the memory and jobfs accordingly is required to prevent the compute resource waste.

Also note that you must include -l storage=scratch/ab12+gdata/yz98 to the qsub command below if the job needs access to /scratch/ab12/ and /g/data/yz98/. Details on our PBS directives page

$ qsub -I -X -P a00 -q normal -l ncpus=1,mem=2GB,jobfs=8GB,walltime=00:30:00,wd

When the interactive job starts on Gadi, execute the followings commands:

# Load module, always specify version number.
$ module load idl/8.8
# Sets the number of threads that IDL uses in thread-pool computations
$ idl
IDL 8.8.0 (linux x86_64 m64).
(c) 2020, Harris Geospatial Solutions, Inc.
Licensed for use by: National Computational Infrastructure - Menadue
License: 242564

IDL's command-line options are available at


This version of IDL uses commercial licences so has no restrictions.

Authors: Mohsin Ali
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