Error when defining function in IDL: "programs can't be compiled in single statement mode"

Question

I'm working with IDL Version 8.0.1, Windows 7 Operating system.

When trying to define a function in the command line, I get the error "programs can't be compiled in single statement mode". Not quite sure how to fix.

Answer 1

Normally you would define functions/procedures in a file, but you can do it from the command line:

IDL> .compile
- function triple, x
-   return, 3 * x
- end
% Compiled module: TRIPLE