Lecture 0: A ``disclaimer''

1. I've been formally taught very little programming (and no IDL).

2. Much of my code is awful (one of the good things about IDL is that you can write it very fast, making it tempting to ``just quickly write'' some uncommented code to see if something works, which you then end up using for months or years).

3. Many people here know much more about much of this subject than me

4. As many websites will show you there is a lot you can learn.

BUT this tutorial is meant to get you started.

It's worth not losing site of where you're trying to get to. There is always a balance between learning a new skill to do something quickly versus using an old skill to do the same thing slowly. You can spend hours getting a routine to run faster, when you could leave it to run and go and do some reading! You don't get a Phd for writing fancy code. Doing a PhD does involve organising three years work though and having tidy, flexible and efficient code is a habit worth gaining early on.

Finally, from ''IDL guru'' David Fanning,

'' Don't worry about it. Everyone I've ever known who leaves an IDL programming class (including the instructor!) laments about how they are going to have to spend the next two weeks re-writing their programs. It's an on-going and never-ending process.

Do what you can, but don't dwell on it. Just try to write better programs in the future. At the end of a career no one wishes they had spent more time revising their programs. :-) ''