Seb's IDL Help Page

About this page

This page is mainly designed to help IDL users on the PACT network at Sussex but may have information of use to others

At the moment it assumes that you have some basic knowledge of IDL and are looking to customize things a bit (if not some of the links below may help)

It also assumes you know something about Unix

I refer to various files and give the local location of these so that local uses can see the latest versions but also link to a static version on these pages.

Getting Started

You will find it very useful to set up an idl directory under your $HOME directory i.e. $HOME/idl.

You need to set up some environment variables. The easiest way to do this may be to copy (and modify if necessary) my startup file ~/sjo/idl/susx_startup into your idl directory (static version).

This file should then be sourced from your .login file

# idl setup
source $HOME/idl/susx_startup

One particularly useful environment variable is IDL_PATH. This specifies the path that IDL will use to find subroutines. On starting IDL directories flagged with a + will be expanded into the PATH to include any subdirectories that contain .pro files. The libraries that are setup in my PATH are explained below.

Another useful one IDL_STARTUP which defines a file of commands which will be executed when idl starts. In my case this is ~/idl/idl_nojournal_startup (static version). Notice that the IDL_STARTUP file is a script rather than an IDL programme. This means it can explictly compile subroutines (e.g. if you want to bypass a routine that would otherwise appear first in the path. However, it cannot execute loops although it can call an IDL programme in my case ~/idl/user_setup.pro (static version)

EMACS

If you use emacs and don't already have one you could create an emacs directory e.g. $HOME/emacs and copy the ~sjo/emacs/emacs ~sjo/emacs/idl.el (static version) and ~sjo/emacs/idl.elc (static version) files into it. (These file was originally discovered by Ian Grivel). You will then need to edit your .emacs file to load ~/emacs/emacs (see ~sjo/.emacs, static version)

There is now a much more sophsticated package which superceeds this called IDLWAVE, which I hope someone will install oneday

Colours

Yo may well find problems with colours as some devices are 24-bit colour and others are 8-bit Some notes on IDL color may be of use to you. To be honest I haven't got my head around this yet.

Templates

It is a very good idea to write your IDL code with proper headers. These will enable others to use your code and you to remember what it did when you come to use it next week. Properly writen headers for a library of routines can also be used to automatically generate an HTML help library.

Libraries

There are a wide variety of IDL libraries available. The most important of these is Astrolib. I provide a seperate page listing Libraries many of which are included in the IDL_PATH set up as above. In the near future I'll put these libraries in a sensible central location.

Other IDL WWW resources

Acknowledgments

Some bits taken from ICSTM IDL Help

Contact addresses and numbers

S.Oliver Sussex.ac.uk
last updated 14th January 2002
original 11th January 2002
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