The original introduction page was very long and mixed tutorial text, examples, and historical notes. This cleaned-up version keeps the core workflow visible and points to the preserved example files.

Before starting, review the setup page so your IDL environment and X11 configuration are correct.

IDL> a = 5
IDL> print, a
IDL> a = [2, 3]
IDL> print, a

IDL is interactive by default. Commands execute as soon as you press return. Arrays use square brackets, indexing is zero-based, and most plotting commands accept keyword arguments rather than method chaining.

For one-off commands, work directly at the prompt. For reusable analysis, put commands in a .pro file and either compile it or run it in batch mode.

idl my_batch_file

# or inside IDL
@my_batch_file

If your workflow needs stdin redirection, use the script page.

• 1-D polynomial fit example
• XY polynomial fit example
• Hydrology contour example
• Irregular surface plot example

The raw source and sample data are here.