Create and draw a polar graph with PI axis using a TF1.

**Author:** Olivier Couet

*This notebook tutorial was automatically generated with ROOTBOOK-izer from the macro found in the ROOT repository on Tuesday, November 29, 2022 at 11:17 AM.*

In [1]:

```
TCanvas *CPol = new TCanvas("CPol","TGraphPolar Examples",500,500);
Double_t rmin = 0;
Double_t rmax = TMath::Pi()*2;
Double_t r[1000];
Double_t theta[1000];
TF1 *fp1 = new TF1("fplot","cos(x)",rmin,rmax);
for (Int_t ipt = 0; ipt < 1000; ipt++) {
r[ipt] = ipt*(rmax-rmin)/1000+rmin;
theta[ipt] = fp1->Eval(r[ipt]);
}
TGraphPolar *grP1 = new TGraphPolar(1000, r, theta);
grP1->SetTitle("");
grP1->SetLineColor(2);
grP1->Draw("AOL");
```

Draw all canvases

In [2]:

```
gROOT->GetListOfCanvases()->Draw()
```