TMultiGraph axis ranges not being used

[tboone42]

Hi-

I’m trying to use a small section of line to project a line and compare its distance to points on a graph, and show it graphically. I’ve been trying to use a TMultiGraph to hold three graphs: one with the points that are “targets”, one that holds a short line segment, and one that is a long line that projects the direction of the line segment. I then try to draw everything on top of each other, but I have limits I want to set in the X and Y that get overridden by the projected line, I’ve tried reading through forums here but I don’t know what my issue is, when I draw the plots I end up with the bounds of my axes expanding to fit the long line in the multigraph, is there a way to override this?

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plot_DCA_calc.C (8.2 KB)

ROOT Version: 06_22_08d
Platform: Not Provided
Compiler: Not Provided

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[couet]

I cannot run your macro because some data are missing. But here is a small example setting the limits of a TMultiGraph.

{
   TCanvas *c = new TCanvas();

   TGraph *g[3];
   Double_t x[10] = {0,1,2,3,4,5,6,7,8,9};
   Double_t y[10] = {1,2,3,4,5,5,4,3,2,1};
   TMultiGraph *mg = new TMultiGraph();
   for (int i=0; i<3; i++) {
      g[i] = new TGraph(10, x, y);
      for (int j=0; j<10; j++) y[j] = y[j]-1;
      mg->Add(g[i]);
   }
   mg->GetXaxis()->SetRangeUser(0.,2.5);
   mg->SetMaximum(1.);
   mg->SetMinimum(-0.5);
   mg->Draw("al*");
}