Creating a color TGraph2D with a large number of points


I am trying to plot approximately 150000 data points into a TGraph2D with colZ, to get a map. However, the required calculation time if horrible, and I don’t know how to fix that.

I have points of the form (x,y,value) and I am reading the date with


take hours… Any idea?

Thanks in advance,

Yes, this technique is very slow with a big number of points and should be used only when really needed. I do not know enough about your data set to tell you more, but my first thought would be to try to fill directly a TH2. 150000 is a 150x100 bins histogram ! so, with a such presision, I am wondering why you need interpolation in addition…