Tutorial IDL

IDL: a small tutorial for DATA studentsF. Spada & C.I. van Tuyll15th February 2005Contents1 Introduction 22 Getting started 33 Links 54 Command line interface 65 Programs 76 Constants and Variables 86.1 Operators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86.2 Conversion functions . . . . . . . . . . . . . . . . . . . . . . . 97 Arrays 107.1 Simple operations . . . . . . . . . . . . . . . . . . . . . . . . . 107.2 Subscripts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 118 Files I/O 149 Program Control 1710 Calling procedures and functions 2011 Graphics 2111.1 Graphics preferences . . . . . . . . . . . . . . . . . . . . . . . 2111.2 Simple plotting . . . . . . . . . . . . . . . . . . . . . . . . . . 2111.3 Contour . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2211.4 Bar plot . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2311.5 Saving your plot. . . . . . . . . . . . . . . . . . . . . . . . . . 2411.6 Useful graphics command . . . . . . . . . . . . . . . . . . . . 2512 Saving and restoring IDL data 2613 Random numbers 2711 Introduction1IDL (Interactive Data Language) is a scienti c computing package, whichcan be used for data analysis and visualisation. IDL is an array based lan-guage, which means that no complicated program routines are needed tocalculatewitharrays. Thetoolsarecalledbyusingacommandlineinterface.This tutorial shows only a glimpse of what you can do with IDL. It takes ...