tornado.C

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/// \file
/// \ingroup tutorial_graphics
/// \notebook
/// Show 3-d polymarker.
///
/// \macro_image
/// \macro_code
///
/// \author Rene Brun
 
void tornado() {
   gBenchmark->Start("tornado");
 
   double PI = 3.141592653;
   int d = 16;
   int numberOfPoints=200;
   int numberOfCircles=40;
 
   // create and open a canvas
   TCanvas *sky = new TCanvas( "sky", "Tornado", 300, 10, 700, 500 );
   sky->SetFillColor(14);
 
   // creating view
   TView *view = TView::CreateView(1,0,0);
   float range = numberOfCircles*d;
   view->SetRange( 0, 0, 0, 4.0*range, 2.0*range, range );
 
   for( int j = d; j < numberOfCircles*d; j += d ) {
 
      // create a PolyMarker3D
      TPolyMarker3D *pm3d = new TPolyMarker3D( numberOfPoints );
 
      float x, y, z;
 
      // set points
      for( int i = 1; i < numberOfPoints; i++ ) {
         float csin = sin(2*PI / (double)numberOfPoints  * (double)i) + 1;
         float ccos = cos(2*PI / (double)numberOfPoints  * (double)i) + 1;
         float esin = sin(2*PI / (double)(numberOfCircles*d) * (double)j) + 1;
         x = j * ( csin + esin );
         y = j * ccos;
         z = j;
         pm3d->SetPoint( i, x, y, z );
      }
 
      // set marker size, color & style
      pm3d->SetMarkerSize( 1 );
      pm3d->SetMarkerColor( 2 + ( d == ( j & d ) ) );
      pm3d->SetMarkerStyle( 3 );
 
      //draw
      pm3d->Draw();
   }
 
   char timeStr[60];
   gBenchmark->Show("tornado");
 
   Float_t ct = gBenchmark->GetCpuTime("tornado");
   sprintf( timeStr, "Execution time: %g sec.", ct);
 
   TPaveText *text = new TPaveText( 0.1, 0.81, 0.9, 0.97 );
   text->SetFillColor( 42 );
   text->AddText("ROOT example: tornado.C");
   text->AddText(timeStr);
   text->Draw();
   sky->Update();
}