COLZ Color scale

ROOT
1

I’d like to know if there was an option to set an arbitrary color scale on 2D-histograms drawn with the “COLZ” option.

Let me explain the situation a little better:
Let’s say I have a 100x100 TH2S with values in the bins ranging from 56 to 1350. ROOT will automatically adjust the color scale from 56 (purple in Color Style 1) to 1350 (red), which is handy. However, I would also like to be able to have a fixed color scale ranging from 0 to 1600, even if there is no bin with such values.

Would anybody know how to do this with ROOT ?
Thanks for the help !

2

here is an example defining a gray scale palette. You can modify it to define le palette you need.

{
   TF2 *f2 = new TF2("f2","0.1+1000*((1-(x-2)*(x-2))*(1-(y-2)*(y-2)))",1,3,1,3);  
   Int_t ncol = 100;
   Int_t colors[ncol];
   TColor *col;
   Double_t dg=1/(Double_t)ncol;
   Double_t grey=0;
   for (Int_t i=0; i<ncol; i++) {
      colors[i]= i+100;
      col = gROOT->GetColor(colors[i]);
      col->SetRGB(grey, grey, grey);
      grey = grey+dg;
   }
   f2->SetContour(ncol);
   gStyle->SetPalette(100,colors);
   f2->Draw("colz");
}
3

Thanks a lot.