Logo ROOT   6.10/09
Reference Guide
graphpolar.C File Reference

Detailed Description

View in nbviewer Open in SWAN Create and draw a polar graph.

pict1_graphpolar.C.png
void graphpolar()
{
// Illustrates how to use TGraphPolar
TCanvas * CPol = new TCanvas("CPol","TGraphPolar Examples",1200,600);
CPol->Divide(2,1);
CPol->cd(1);
Double_t xmin=0;
Double_t x[1000];
Double_t y[1000];
Double_t xval1[20];
Double_t yval1[20];
TF1 * fplot = new TF1("fplot","cos(2*x)*cos(20*x)",xmin,xmax);
for (Int_t ipt = 0; ipt < 1000; ipt++){
x[ipt] = ipt*(xmax-xmin)/1000+xmin;
y[ipt] = fplot->Eval(x[ipt]);
}
TGraphPolar * grP = new TGraphPolar(1000,x,y);
grP->SetLineColor(2);
grP->SetLineWidth(2);
grP->SetFillStyle(3012);
grP->SetFillColor(2);
grP->Draw("AFL");
for (Int_t ipt = 0; ipt < 20; ipt++){
xval1[ipt] = x[1000/20*ipt];
yval1[ipt] = y[1000/20*ipt];
}
TGraphPolar * grP1 = new TGraphPolar(20,xval1,yval1);
grP1->SetMarkerStyle(29);
grP1->SetMarkerSize(2);
grP1->SetMarkerColor(4);
grP1->SetLineColor(4);
grP1->Draw("CP");
// Update, otherwise GetPolargram returns 0
CPol->Update();
grP1->GetPolargram()->SetNdivPolar(703);
CPol->cd(2);
Double_t x2[30];
Double_t y2[30];
Double_t ex[30];
Double_t ey[30];
for (Int_t ipt = 0; ipt < 30; ipt++){
x2[ipt] = x[1000/30*ipt];
y2[ipt] = 1.2 + 0.4*sin(TMath::Pi()*2*ipt/30);
ex[ipt] = 0.2+0.1*cos(2*TMath::Pi()/30*ipt);
ey[ipt] = 0.2;
}
TGraphPolar * grPE = new TGraphPolar(30,x2,y2,ex,ey);
grPE->SetMarkerStyle(22);
grPE->SetMarkerSize(1.5);
grPE->SetMarkerColor(5);
grPE->SetLineColor(6);
grPE->SetLineWidth(2);
grPE->Draw("EP");
CPol->Update();
grPE->GetPolargram()->SetTextSize(0.03);
grPE->GetPolargram()->SetTwoPi();
}
Author
Olivier Couet

Definition in file graphpolar.C.