parallelcoordtrans.C

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/// \file
/// \ingroup tutorial_gl
/// Script illustrating the use of transparency with ||-Coord.
/// It displays the same data set twice. The first time without transparency and
/// the second time with transparency. On the second plot, several clusters
/// appear.
///
/// \macro_image(nobatch)
/// \macro_code
///
/// \authors Timur Pocheptsov, Olivier Couet
 
#include <cassert>
 
#include "TParallelCoordVar.h"
#include "TParallelCoord.h"
#include "TNtuple.h"
#include "TCanvas.h"
#include "TRandom.h"
#include "TColor.h"
#include "TStyle.h"
#include "TError.h"
#include "TList.h"
#include "TROOT.h"
 
namespace ROOT {
namespace GLTutorials {
 
Double_t r1, r2, r3, r4, r5, r6, r7, r8, r9;
TRandom r;
 
//______________________________________________________________________
void generate_random(Int_t i)
{
   const Double_t dr = 3.5;
 
   r.Rannor(r1, r4);
   r.Rannor(r7, r9);
 
   r2 = (2 * dr * r.Rndm(i)) - dr;
   r3 = (2 * dr * r.Rndm(i)) - dr;
   r5 = (2 * dr * r.Rndm(i)) - dr;
   r6 = (2 * dr * r.Rndm(i)) - dr;
   r8 = (2 * dr * r.Rndm(i)) - dr;
}
 
} // namespace GLTutorials
} // namespace ROOT
 
void parallelcoordtrans(bool gl = true)
{
   // This macro shows how to use parallel coords and semi-transparent lines
   //(the system color is updated with alpha == 0.01 (1% opaque).
 
   using namespace ROOT::GLTutorials;
 
   Double_t s1x = 0., s1y = 0., s1z = 0.;
   Double_t s2x = 0., s2y = 0., s2z = 0.;
   Double_t s3x = 0., s3y = 0., s3z = 0.;
 
   gStyle->SetCanvasPreferGL(gl);
   TCanvas *c1 = new TCanvas("parallel coors", "parallel coords", 0, 0, 900, 1000);
 
   if (!c1->UseGL() && !c1->IsWeb() && !gVirtualX->InheritsFrom("TGCocoa"))
      ::Warning("parallelcoordtrans",
                "To have real transparency in a canvas graphics, you need either OpenGL or Mac/Cocoa or Web rendering enabled");
 
   TNtuple *const nt = new TNtuple("nt", "Demo ntuple", "x:y:z:u:v:w:a:b:c");
 
   for (Int_t i = 0; i < 1500; ++i) {
      r.Sphere(s1x, s1y, s1z, 0.1);
      r.Sphere(s2x, s2y, s2z, 0.2);
      r.Sphere(s3x, s3y, s3z, 0.05);
 
      generate_random(i);
      nt->Fill(r1, r2, r3, r4, r5, r6, r7, r8, r9);
 
      generate_random(i);
      nt->Fill(s1x, s1y, s1z, s2x, s2y, s2z, r7, r8, r9);
 
      generate_random(i);
      nt->Fill(r1, r2, r3, r4, r5, r6, r7, s3y, r9);
 
      generate_random(i);
      nt->Fill(s2x - 1, s2y - 1, s2z, s1x + .5, s1y + .5, s1z + .5, r7, r8, r9);
 
      generate_random(i);
      nt->Fill(r1, r2, r3, r4, r5, r6, r7, r8, r9);
 
      generate_random(i);
      nt->Fill(s1x + 1, s1y + 1, s1z + 1, s3x - 2, s3y - 2, s3z - 2, r7, r8, r9);
 
      generate_random(i);
      nt->Fill(r1, r2, r3, r4, r5, r6, s3x, r8, s3z);
   }
 
   c1->Divide(1, 2);
   c1->cd(1);
 
   // ||-Coord plot without transparency
   nt->Draw("x:y:z:u:v:w:a:b:c", "", "para");
   TParallelCoord *const para1 = (TParallelCoord *)gPad->GetListOfPrimitives()->FindObject("ParaCoord");
   assert(para1 != nullptr && "parallelcoordtrans, 'ParaCoord' is null");
 
   para1->SetLineColor(25);
   TParallelCoordVar *pcv = (TParallelCoordVar *)para1->GetVarList()->FindObject("x");
   pcv->SetHistogramHeight(0.);
 
   pcv = (TParallelCoordVar *)para1->GetVarList()->FindObject("y");
   pcv->SetHistogramHeight(0.);
 
   pcv = (TParallelCoordVar *)para1->GetVarList()->FindObject("z");
   pcv->SetHistogramHeight(0.);
 
   pcv = (TParallelCoordVar *)para1->GetVarList()->FindObject("a");
   pcv->SetHistogramHeight(0.);
 
   pcv = (TParallelCoordVar *)para1->GetVarList()->FindObject("b");
   pcv->SetHistogramHeight(0.);
 
   pcv = (TParallelCoordVar *)para1->GetVarList()->FindObject("c");
   pcv->SetHistogramHeight(0.);
 
   pcv = (TParallelCoordVar *)para1->GetVarList()->FindObject("u");
   pcv->SetHistogramHeight(0.);
 
   pcv = (TParallelCoordVar *)para1->GetVarList()->FindObject("v");
   pcv->SetHistogramHeight(0.);
 
   pcv = (TParallelCoordVar *)para1->GetVarList()->FindObject("w");
   pcv->SetHistogramHeight(0.);
 
   // ||-Coord plot with transparency
   // We modify a 'system' color! You'll probably
   // have to restart ROOT or reset this color later.
   TColor *const col26 = gROOT->GetColor(26);
   assert(col26 != nullptr && "parallelcoordtrans, color with index 26 not found");
 
   col26->SetAlpha(0.01);
 
   c1->cd(2);
   nt->Draw("x:y:z:u:v:w:a:b:c", "", "para");
   TParallelCoord *const para2 = (TParallelCoord *)gPad->GetListOfPrimitives()->FindObject("ParaCoord");
   assert(para2 != nullptr && "parallelcoordtrans, 'ParaCoord' is null");
 
   para2->SetLineColor(26);
 
   pcv = (TParallelCoordVar *)para2->GetVarList()->FindObject("x");
   pcv->SetHistogramHeight(0.);
 
   pcv = (TParallelCoordVar *)para2->GetVarList()->FindObject("y");
   pcv->SetHistogramHeight(0.);
 
   pcv = (TParallelCoordVar *)para2->GetVarList()->FindObject("z");
   pcv->SetHistogramHeight(0.);
 
   pcv = (TParallelCoordVar *)para2->GetVarList()->FindObject("a");
   pcv->SetHistogramHeight(0.);
 
   pcv = (TParallelCoordVar *)para2->GetVarList()->FindObject("b");
   pcv->SetHistogramHeight(0.);
 
   pcv = (TParallelCoordVar *)para2->GetVarList()->FindObject("c");
   pcv->SetHistogramHeight(0.);
 
   pcv = (TParallelCoordVar *)para2->GetVarList()->FindObject("u");
   pcv->SetHistogramHeight(0.);
 
   pcv = (TParallelCoordVar *)para2->GetVarList()->FindObject("v");
   pcv->SetHistogramHeight(0.);
 
   pcv = (TParallelCoordVar *)para2->GetVarList()->FindObject("w");
   pcv->SetHistogramHeight(0.);
}