Re: Viewpoint in 3D

Roger,

I thought that I had already sent you the script writing the labels. Here it is again.

Rene Brun

Roger Mason wrote:
> Hi Rene,
>
> Rene Brun <Rene.Brun_at_cern.ch> writes:
>
>
>> Try the script in the attachment. Use TPad::SetTheta, Phi to set the
>> viewing angle.
>> Yes, we have some incoherent behavior between settings via TPad and TView.
>>
>
> When I run the version printed below I>
> get the following:
>
> root [0] .x PlotHeights_6.C()
> File contains 7 control points
> Error: illegal pointer to class object view 0x0 393 PlotHeights_6.C:44:
> *** Interpreter error recovered ***
>
> Is that what you mean by incoherent?
>
> Is it possible to have the view from gPad->SetPhi(-90),
> gPad->SetTheta(-89.99) and have the points labelled?
>
> Thanks very much,
>
> Roger
>
> // ================== PlotHeights_x.C
> #include <iostream>
>
> void PlotHeights_6 ()
> {
> gROOT->Reset();
>
> // TString datdir = "../data/";
> // TString fname = TString(filename);
> // TString file = datdir+fname;
>
> TCanvas *c = new TCanvas("c","test",0,0,1024,768);
> c->Divide(2,1);
>
> TGraph2D *dt = new TGraph2D("graph.dat");
> Int_t n = dt->GetN();
> cout << "File contains " << n << " control points" << endl;
>
> Double_t* x = dt->GetX();
> Double_t* y = dt->GetY();
> Double_t* z = dt->GetZ();
> Double_t xmax = dt->GetXmax();
> Double_t xmin = dt->GetXmin();
> Double_t ymax = dt->GetYmax();
> Double_t ymin = dt->GetYmin();
>
> // What the students get
> c->cd(1);
> gPad->SetPhi(-90); // Viewpoint
> gPad->SetTheta(-89.99);
> dt->SetMarkerStyle(8); // Marker for the control points
> dt->SetTitle("");
> dt->Draw("AP");
>
> Double_t xyz[3], uv[2];
> TView *view = gPad->GetView();
>
> TText t;
> t.SetTextSize(0.035);
> for (Int_t i=0;i<n;i++) {
> xyz[0] = dt->GetX()[i];
> xyz[1] = dt->GetY()[i];
> xyz[2] = dt->GetZ()[i];
> view->WCtoNDC(xyz,uv); // Line 44, error
> t->DrawText(uv[0]+0.01,uv[1],Form("%d",z[i]));
> }
>
> // TString imagefile = "../images/"+fname+".eps";
> // gPad->Print(imagefile); // Print the current pad (only)
>
> // The solution, in 3D viewed from above
> gStyle->SetPalette(1);
>
>
> Double_t contours[] = {20,40,60,80,100,120,140,160,180,200};
>
> c->cd(2);
> gPad->SetPhi(0); // Viewpoint
> gPad->SetTheta(90);
>
> TH2D* h = new TH2D();
> h = dt->GetHistogram(); // Get histo interpolated between
> // control points in dt.
> h->SetContour(10,contours); // Set 10 contour levels (default is 20)
> h->Draw("surf2"); // Draw interpolated points as surface
> h->Draw("cont1 same"); // Contour the surface
> dt->SetTitle("");
> dt->SetMarkerStyle(8); // Marker for the control points
> dt->Draw("p same"); // Superimpose the control points
>
>
> // TString imagefile = "../images/"+fname+"_solution.eps";
> // gPad->Print(imagefile); // Print the current pad (only)
>
> return c;
> }
>
>