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Anonymous
November 19, 2010
Solved

Histogram Worksheet - so sloooooow

  • November 19, 2010
  • 1 reply
  • 3881 views

Hi, I am trying to use a histogram as a means to measure image uniformity. To do this I first down sample the raw image to a binned version (this is the tabled data in the worksheet). I then partition this downsampled image into a histogram and use this for a calculation. As my images can have a widely differing intensity profiles, I want to keep the number of bins fixed rather than bin with an absolute value of intensity. I thus normalise the bin.

The whole worksheet is extremely slow

Is there anything I can do to speed it up.

Thanks

Jason

BTW, I have finally converted to mathcad 15!

Best answer by StuartBruff

Jason,

does the attached do something like what you want?

The histogram function requires that you either provide the number of bins for equal spacing (which is what I think you want) or a vector of bin end points (nbins+1 points). I think all you need to do is defined nbins:=20 and the define P:=histogram(nbins,Z), etc.

Stuart

Message was edited by: Stuart_Bruff - worksheet corrected to create P1 from Z1 rather than Z

1 reply

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StuartBruff23-Emerald V
23-Emerald V
November 19, 2010

Could you please post the worksheet in an earlier format as well? M11 preferably, M13 if not.

Stuart

A
Anonymous
November 19, 2010

Here You Go

S
StuartBruff23-Emerald V
23-Emerald V
November 19, 2010

Jason,

I've just opened your worksheet and the first thing I notice is that you actually calculate 800+ bins for the histograms P & P1 at the start of the collapsed area rather than the 20 the text states ... I'm not sure that you are caculating the correct thing, looking at .

Stuart

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