An array is a numbered group of variables, all of the same type.
Vectors are just 1D arrays
You can define an array by :
IDL> an_array=[3, 5, 6, 2.5, 100, 27.7]
Since we have mixed up floats and integers in this expression; IDL forces all the integers to floats. If you define an array using integers only then IDL will leave them as integers.
IDL> foo=fltarr(100,100); 0.0, 0.0, 0.0, 0.0 ... 0.0 IDL> foo=intarr(100,100); 0, 0, 0, 0, ... 0 IDL> foo=strarr(100,100); '', '', '', '', ... '' IDL> foo=indgen(100) ; 0, 1, 2, 3, ... 99 IDL> foo=findgen(100) ; 0.0, 1.0, 2.0, 3.0, ... 99.0
Look up ``fltarr'', ``indgen'' and any other IDL procedures that you come across and aren't familar with using ``?'' at the IDL prompt.