How to use IDL in a Workflows application

Terradue [archive] Ellip Workflows
1

IDL, short for Interactive Data Language, is a programming language used for data analysis.

There are a few steps to follow to use IDL code in a Workflows application:

  1. Install IDL 

  2. Create a SAVE (.sav) file of the IDL Program Files (.pro) 

  3. Create a virtual buffer

  4. Export the IDL license environment variable

  5. Invoke the IDL SAVE file

Installing IDL

Run the simple step below on the Developer Cloud Sandbox shell:

sudo yum install -y idl

Creating a SAVE (.sav) file

Creating a virtual buffer

The virtual buffer is a “fake” screen required by IDL to run correctly.
Run the simple steps below on the Developer Cloud Sandbox shell:

sudo yum install -y Xvfb
sudo Xvfb :0 -screen 0 3600x1800x24 &

Exporting the IDL license environment variable

Before invoking the IDL SAVE file, add the definition of the IDL license environment variable:

export LM_LICENSE_FILE=1700@idl.terradue.int

Invoking the IDL SAVE file

The file Hello.sav was created from the Step 1 above.
To invoke it, do:

idl -rt=/tmp/Hello.sav