Smoother COLZ/TH2 Plots?


I do have the 2D (COLZ) plot and would like to make it smoother

This is what I use in my rootlogon.C but is not what I want


    const Int_t NRGBs = 5;
    const Int_t NCont = 104;

    Double_t stops[NRGBs] = { 0.00, 0.34, 0.61, 0.84, 1.00 };
    Double_t red[NRGBs]   = { 0.00, 0.00, 0.87, 1.00, 0.51 };
    Double_t green[NRGBs] = { 0.00, 0.81, 1.00, 0.20, 0.00 };
    Double_t blue[NRGBs]  = { 0.51, 1.00, 0.12, 0.00, 0.00 };

    TColor::CreateGradientColorTable(NRGBs, stops, red, green, blue, NCont);


~ [/code]

The Rainbow color map
How to define a smooth color palette ?

The palette you have is itself very smooth but your histogram has s very small number of bin … that’s why you do not get a smooth result on the plot itself.


Thanks for the answers - However, one more question - How I get rid of the “colored” area where I do not have values? You can see that my values are always below the “diagonal” (ie where also I ve put “COLTEXTZ”) but I would expect that the “upper” part would be filled with white but this is not the case… How can I fix this ?



see the rule here

the best would be to change the color around 0 to white

hi again

would it be possible to give an example how to do this ? It seems that I cannot really do it…



you can define your own color map has explained here: … or-palette