Random from interpolated TGraph2D

ROOT
1

Hello,
I have a some fairly coarsely distributed points in a TGraph 2D, and I’d like to use a simple interpolation (linear is fine) then pull random points from the result - along the lines of the GetRandom2 method in TH2, but using the interpolation.
Any suggestions on how to do this?
thanks!

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2

I guess you can get random points in the X,Y plane of your TGraph2D and for each of them retrieve the Z value using Interpolate.

3

Thanks - but I was hoping to draw points with a probability based on the (interpolated) z-axis value. I can always hack something together based on your suggestion, but wondered if this functionality already existed for TGraph2D - the interpolation etc is already there.

4

TGraph2D does not have the GetRandom2 method like TH2. But it has GetHistogram which returns a TH2D produced thanks to the Delaunay triangles of the TGraph2D. So you can use GetRandom2 on the TH2D returned by GetHistogram.

5

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