It defines and set a user's palette, and use polar system.
 
void glrose()
{
   const Int_t paletteSize = 10;
 
      {0.80f, 0.55f, 0.40f,
       0.85f, 0.60f, 0.45f,
       0.90f, 0.65f, 0.50f,
       0.95f, 0.70f, 0.55f,
       1.f,   0.75f, 0.60f,
       1.f,   0.80f, 0.65f,
       1.f,   0.85f, 0.70f,
       1.f,   0.90f, 0.75f,
       1.f,   0.95f, 0.80f,
       1.f,   1.f,   0.85f};
 
   Int_t palette[paletteSize] = {0};
 
 
   for (
Int_t i = 0; i < paletteSize; ++i)
 
 
 
   TCanvas *cnv = 
new TCanvas(
"glc", 
"Surface sample", 200, 10, 600, 550);
 
 
                           "\"glsurf2pol\" option + user defined palette.");
 
   TPad *rosePad  = 
new TPad(
"box", 
"box", 0.04, 0.04, 0.96, 0.8);
 
 
 
   TF2 *fun = 
new TF2(
"a", 
"cos(y)*sin(x)+cos(x)*sin(y)", -6, 6, -6, 6);
 
}
R__EXTERN TStyle * gStyle
 
virtual void SetFillColor(Color_t fcolor)
Set the fill area color.
 
static Int_t GetColor(const char *hexcolor)
Static method returning color number for color specified by hex color string of form: "#rrggbb",...
 
virtual void SetNpx(Int_t npx=100)
Set the number of points used to draw the function.
 
A 2-Dim function with parameters.
 
virtual void SetContour(Int_t nlevels=20, const Double_t *levels=nullptr)
Set the number and values of contour levels.
 
virtual void SetNpy(Int_t npy=100)
Set the number of points used to draw the function.
 
void Draw(Option_t *option="") override
Draw this function with its current attributes.
 
The most important graphics class in the ROOT system.
 
TVirtualPad * cd(Int_t subpadnumber=0) override
Set Current pad.
 
void Draw(Option_t *option="") override
Draw Pad in Current pad (re-parent pad if necessary).
 
A Pave (see TPave) with a text centered in the Pave.
 
void Draw(Option_t *option="") override
Draw this pavelabel with its current attributes.
 
void SetPalette(Int_t ncolors=kBird, Int_t *colors=nullptr, Float_t alpha=1.)
See TColor::SetPalette.
 
void SetCanvasPreferGL(Bool_t prefer=kTRUE)