IDL Programming Concepts

We'll start with the basic concepts that you need to get started. There are different ways you can use IDL, depending on what you want to achieve.

First, a quick definition of some terms you need to know:

Scope—Refers to the context in which variables are accessible to other routines.

Interactive mode—Refers to the IDL command line, where you can type a line or several lines of code and immediately execute those commands.

Main programs—Programs with the same scope as the IDL command line. You can save these programs, but they cannot be called by other routines.

Named programs—Refers to IDL procedures and functions, also called IDL routines. Named programs have their own scope. They can be called by other routines.

Graphical User Interface (GUI) programs—IDL provides widget programming routines and iTools for developing graphical interfaces.