TCanvas *vC1; TGraph *grxy, *grin, *grout; void DrawSmooth(Int_t pad, const char *title, const char *xt, const char *yt) { vC1->cd(pad); TH1F *vFrame = gPad->DrawFrame(0,0,15,150); vFrame->SetTitle(title); vFrame->SetTitleSize(0.2); vFrame->SetXTitle(xt); vFrame->SetYTitle(yt); grxy->SetMarkerColor(kBlue); grxy->SetMarkerStyle(21); grxy->SetMarkerSize(0.5); grxy->Draw("P"); grin->SetMarkerColor(kRed); grin->SetMarkerStyle(5); grin->SetMarkerSize(0.7); grin->Draw("P"); grout->DrawClone("LP"); } void approx() { //********************************************** // Macro to test interpolation function Approx // Author: Christian Stratowa, Vienna, Austria. // Created: 26 Aug 2001 //********************************************** // test data (square) Int_t n = 11; Double_t x[] = {1,2,3,4,5,6,6,6,8,9,10}; Double_t y[] = {1,4,9,16,25,25,36,49,64,81,100}; grxy = new TGraph(n,x,y); // x values, for which y values should be interpolated Int_t nout = 14; Double_t xout[] = {1.2,1.7,2.5,3.2,4.4,5.2,5.7,6.5,7.6,8.3,9.7,10.4,11.3,13}; // create Canvas vC1 = new TCanvas("vC1","square",200,10,700,700); vC1->Divide(2,2); // initialize graph with data grin = new TGraph(n,x,y); // interpolate at equidistant points (use mean for tied x-values) TGraphSmooth *gs = new TGraphSmooth("normal"); grout = gs->Approx(grin,"linear"); DrawSmooth(1,"Approx: ties = mean","X-axis","Y-axis"); // re-initialize graph with data // (since graph points were set to unique vales) grin = new TGraph(n,x,y); // interpolate at given points xout grout = gs->Approx(grin,"linear", 14, xout, 0, 130); DrawSmooth(2,"Approx: ties = mean","",""); // print output variables for given values xout Int_t vNout = grout->GetN(); Double_t vXout, vYout; for (Int_t k=0;k<vNout;k++) { grout->GetPoint(k, vXout, vYout); cout << "k= " << k << " vXout[k]= " << vXout << " vYout[k]= " << vYout << endl; } // re-initialize graph with data grin = new TGraph(n,x,y); // interpolate at equidistant points (use min for tied x-values) // grout = gs->Approx(grin,"linear", 50, 0, 0, 0, 1, 0, "min"); grout = gs->Approx(grin,"constant", 50, 0, 0, 0, 1, 0.5, "min"); DrawSmooth(3,"Approx: ties = min","",""); // re-initialize graph with data grin = new TGraph(n,x,y); // interpolate at equidistant points (use max for tied x-values) grout = gs->Approx(grin,"linear", 14, xout, 0, 0, 2, 0, "max"); DrawSmooth(4,"Approx: ties = max","",""); // cleanup delete gs; }