[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: Not where

bowman@null.edu (Kenneth P. Bowman) writes:
> I often find myself using WHERE to divide an array into two parts.  I do
> one operation on the first part and a different operation on the second
> part.
> It would be nice to have an auxiliary array containing all the indices
> that are *not* returned by WHERE in i.  For example, it would be nice to
> do
> ...

I think I've asked for this before on this list, and I agree with you
wholeheartedly.  I don't believe there's anyway to simulate the
desired feature in IDL without doing another operation.  

The matrix approach doesn't always seem to be appropriate.  (For
example, working on very large arrays, one wants to avoid as many
computations as possible.  The matrix approach actually *compounds*
the number of computations).


Craig B. Markwardt, Ph.D.         EMAIL:    craigmnet@cow.physics.wisc.edu
Astrophysics, IDL, Finance, Derivatives | Remove "net" for better response