| Re: setting histogram bin sizes? [message #61702 is a reply to message #61608] |
Sat, 26 July 2008 12:33  |
dasergatskov
Messages: 1
Registered: July 2008
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Junior Member |
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On Jul 22, 10:52 am, "Jeff N." <jeffnettles4...@gmail.com> wrote:
> Hi folks,
>
> I'm looking for suggestions for a way to set bin sizes for a histogram
> when I don't know much about the data before calculating the
> histogram. Here's my situation: I'm putting together some code that
> takes a hyperspectral image cube and extracts a series of one-band
> parameters from the cube (band depth at a certain wavelength, etc.).
> In trying to assess which of these parameters is most useful for our
> particular application i thought about calculating a histogram for
> each parameter. The problem is that these parameter images (one band,
> floating point images per parameter) will not necessarily fall into
> the same range. Many have possible values of 0 - 1, but they won't
> necessarily take up that entire range. Some however, will not have
> possible values of 0 - 1, but could instead have numbers in the 10s or
> even hundreds. Some parameters have values that are actually in log
> space.
>
> I know that I could simply set the NBINS keyword to HISTOGRAM(), but
> then the question would become how many bins to use? I did some quick
> searching, and there are a few attempts at calculating bin sizes or
> the number of bins on Wikipedia (http://en.wikipedia.org/wiki/
> Histogram). Short of any other information, i am going to use an
> equation from that page that is at least based on the standard
> deviation of the data. But, since I don't have a lot to go on, I
> would very much like to have input from anyone on this newsgroup who
> might have any suggestions for me.
>
> Thanks,
> Jeff
I found Kevin Knuth (http://www.huginn.com/knuth/) paper
Optimal Data-Based Binning for Histograms
http://arxiv.org/abs/physics/0605197
to be quite useful.
Sincerely,
Dmitri.
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