Histogram (was: Mad MAX)

[Struan Gray <struan.gray(at)sljus.lu.se>]

Martin Schultz, mgs@io.harvard.edu writes:

> it seems to me that you have posted at least 10
> different useful things one can do with HISTOGRAM
> over the last year.

    Can't let David have all the glory :-)


>  you should really write a HISTOGRAM tutorial!

    It's (sort of) on my list of things to do - we do some cool spectral
analysis with 2D histograms - but don't hold your breath.

	HISTOGRAM is a hidden gem that works really, really fast,
especially if you already know enough about your data to customise the
binning for speed.  Once you've wrapped your brain round the problem
of how the REVERSE_INDICES array is constructed some very powerful
things become possible. HISTOGRAM's documentation does actually talk
about how much faster than WHERE it can be for some sorts of
searching, but the docs for WHERE are silent on the issue.


Struan