Total number of events in the plots

cosmologist wrote on Dec 07, 2010

Is there a way to have IRAF tell you the total number of events in the plots (can IRAF tell you how many bins it put the data into)?

Is it in the header? How can I find out?
Thanks

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Mike Fitzpatrick wrote on Dec 07, 2010

A plot from what what task? When you say 'event' do you mean something like an X-ray event? Do you mean a 'bin' as in histogram? The answer will depend highly on the task being used, there is no general rule.

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cosmologist wrote on Dec 07, 2010

A plot of a Flat image for example, after using flatcombine and getting the output Flat image.

I am converting the result from a fits file to another kind and the other image seems to be more detailed that the original fits one, so I thought maybe if I check the number of events in each file I can understand the difference between the 2 plots. I can attach them here if that helps.

Thanks

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Mike Fitzpatrick wrote on Dec 07, 2010

And so how are you generating the 'plot'? Is it a line/column plot through the image, a histogram of the 2-D image, the output of some other task....etc.

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cosmologist wrote on Dec 07, 2010

Oh, yea sorry. It is a histogram of the 2-D image. Created using splot.

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cosmologist wrote on Dec 07, 2010

Does the question make more sense now?

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Mike Fitzpatrick wrote on Dec 07, 2010

It makes sense, I'm away at a meeting so replies are slow.

The histogram in SPLOT is just a graphics line style, it isn't a real histogram. The count of events in that case is just the pixel value listing which you can get with a task like LISTPIXELS or WTEXTIMAGE. If you want a real histogram, see the IMHISTOGRAM or PHISTOGRAM task help pages.

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cosmologist wrote on Dec 07, 2010

Thanks a lot.
That helped.

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Last post on Dec 07, 2010