Hi!
Is it possible to set the range of the z-axis in a “colz” plot of a TH2 by the result of a TCutG? I have scanned the forum for this but couldn’t find any solution.
I attach a slightly changed hsimple.C to show what I mean more clearly.
After you have run it, you will see on the right half a cut of the left histogram, but the color range of the z-axis still uses all of the histogram (starting at zero). It would be nice if a cutg could also stretch the range of the z-axis automatically? Or should I create a new histogram with the cut and then plot that?
Cheers,
Michael
myhsimple.C (2.6 KB)
When an histogram is drawn with option COLZ the entire pallette is always used. Try to zoom the palette axis to see that. In your case it is the same. And I think it is better that way than doing (as you suggest) an automatic rescaling because, most of the time, when you do a cut, you want to compare the result with other plots with different cuts or without cut. Imagine the palette changes for every plot (that is what we will get if we do what you suggest), any comparison will be a nightmare ! The best way in you case is to redefine the palette to get the colors your like the most.
I see your point, the comparison issue is indeed valid.
Also my application is crossing constantly the area of T(AS)Image, so I might be confusing my expectations of what an operation would do, I’m sorry for that, maybe it is not a good idea anyway to use ROOT for CCD analysis?
(See also my new question which i didn’t want to attach here for proper naming/archiving of the issue).
E.g. the display of 1 million cells is really bringing my laptop to its knees, if one by accident picks the wrong option, ‘colz’ is fine though, although I don’t understand why the new draw panel’s appearance time seems to be proportional to the number of cells?
It would be nice if you’d share your opinion on using ROOT for CCD analysis (something like “no, that should be okay” or “no, i’d never do that!” 
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Thanks for your help, so I will play around a bit with the definition of my own palettes, there are already many good tips for that in the forum.
Cheers,
Michael