multipalette.C File Reference

Detailed Description

Draw color plots using different color palettes.

As only one palette is active, one need to use TExec to be able to display plots using different palettes on the same pad.

When a pad is painted, all its elements are painted in the sequence of Draw calls (See the difference between Draw and Paint in the TPad documentation); for TExec it executes its command - which in the following example sets palette for painting all objects painted afterwards. If in the next pad another TExec changes the palette, it doesn’t affect the previous pad which was already painted, but it will affect the current and those painted later.

The following macro illustrate this feature.

 
#include "TStyle.h"
#include "TColor.h"
#include "TF2.h"
#include "TExec.h"
#include "TCanvas.h"
 
void Pal1()
{
   static Int_t colors[50];
   static Bool_t initialized = kFALSE;
 
   Double_t Red[3] = {1.00, 0.00, 0.00};
   Double_t Green[3] = {0.00, 1.00, 0.00};
   Double_t Blue[3] = {1.00, 0.00, 1.00};
   Double_t Length[3] = {0.00, 0.50, 1.00};
 
   if (!initialized) {
      Int_t FI = TColor::CreateGradientColorTable(3, Length, Red, Green, Blue, 50);
      for (int i = 0; i < 50; i++)
         colors[i] = FI + i;
      initialized = kTRUE;
      return;
   }
   gStyle->SetPalette(50, colors);
}
 
void Pal2()
{
   static Int_t colors[50];
   static Bool_t initialized = kFALSE;
 
   Double_t Red[3] = {1.00, 0.50, 0.00};
   Double_t Green[3] = {0.50, 0.00, 1.00};
   Double_t Blue[3] = {1.00, 0.00, 0.50};
   Double_t Length[3] = {0.00, 0.50, 1.00};
 
   if (!initialized) {
      Int_t FI = TColor::CreateGradientColorTable(3, Length, Red, Green, Blue, 50);
      for (int i = 0; i < 50; i++)
         colors[i] = FI + i;
      initialized = kTRUE;
      return;
   }
   gStyle->SetPalette(50, colors);
}
 
void multipalette()
{
   TCanvas *c3 = new TCanvas("c3", "C3", 0, 0, 600, 400);
   c3->Divide(2, 1);
   TF2 *f3 = new TF2("f3", "0.1+(1-(x-2)*(x-2))*(1-(y-2)*(y-2))", 1, 3, 1, 3);
   f3->SetLineWidth(1);
   f3->SetLineColor(kBlack);
 
   c3->cd(1);
   f3->Draw("surf1");
   TExec *ex1 = new TExec("ex1", "Pal1();");
   ex1->Draw();
   f3->Draw("surf1 same");
 
   c3->cd(2);
   f3->Draw("surf1");
   TExec *ex2 = new TExec("ex2", "Pal2();");
   ex2->Draw();
   f3->Draw("surf1 same");
}

Author

Olivier Couet

Definition in file multipalette.C.