第一个程序IDL

终于安装完了UBUNTU，并且把IDL安转好了，运行第一个程序：

http://physics.nyu.edu/grierlab/idl_html_help/intro_program3.html

Start IDL

At the IDL command line, enter the following:

   A = 2 

Enter .RUN at the IDL command line. The command line prompt changes from IDL> to -.

Enter the following:

   A = A * 2 
   PRINT, A 
   END 

This creates a main-level program, which compiles and executes. IDL prints 4.

Enter .GO at the IDL command line. The main-level program is executed again, and now IDL prints 8.