[ROOT] Maximum number of points in bins of a scatterplot

From: Thomas Kluge (kluget@mail.desy.de)
Date: Wed Mar 06 2002 - 14:00:32 MET 

Hi Rooters,

in THistPainter the constant

const Int_t <http://root.cern.ch/root/html/ListOfTypes.html#Int_t> kNMAX = 2000;

controls how many dots will be drawn in a bin of a TH2 with scatter plot 
option.

In the implementation of THistPainter::PaintScatterPlot() I found:

      dz = zmax - zmin;
      if (dz >= kNMAX || zmax < 1) {
         scale = (kNMAX-1)/dz;
         if (ncells > 10000) scale /= 5;
         ltest = kTRUE;
      }

so the density of the points is adjusted in two steps right now.

I would appreciate some means to set this behaviour by the user per 
histogram. Either one could specify the
maximum number of points per bin or the sum for the whole histogram. (I 
would prefer the latter).

Best regards,

Thomas Kluge

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