23    TF2 *
f = 
new TF2(
"f", 
"[0]*cos(x)*cos(y)", -1, 1, -1, 1);
    60    double x[11] = {-0.500, -0.5, -0.5, -0.5, -0.5, -0.5, -0.5, -0.5, -0.5, -0.5, -0.500};
    61    double y[11] = {-0.985, -0.8, -0.6, -0.4, -0.2,  0.0,  0.2,  0.4,  0.6,  0.8,  0.985};
    63    for (
int i = 0; i < 11; ++i) z[i] = s*
cos(x[i])*
cos(y[i]);
    66    double xx[2] = {-0.5, -0.5};
    67    double yy[2] = {-0.985, -0.985};
    68    double zz[2] = {0.11, s*
cos(-0.5)*
cos(-0.985)};
 virtual void SetTitleOffset(Float_t offset=1)
Set distance between the axis and the axis title Offset is a correction factor with respect to the "s...
virtual void SetLineWidth(Width_t lwidth)
Set the line width. 
virtual void Draw(Option_t *option="")
Draw this function with its current attributes. 
virtual void SetNpx(Int_t npx=100)
Set the number of points used to draw the function. 
virtual void SetTheta(Double_t theta=30)
R__EXTERN TStyle * gStyle
virtual void SetNdivisions(Int_t n=510, Bool_t optim=kTRUE)
Set the number of divisions for this axis. 
virtual void SetLineColorAlpha(Color_t lcolor, Float_t lalpha)
Set a transparent line color. 
TAxis * GetXaxis() const
Get x axis of the function. 
A 3-dimensional polyline. 
virtual void Draw(Option_t *option="")
Default Draw method for all objects. 
void CenterTitle(Bool_t center=kTRUE)
Center axis title. 
virtual Double_t Integral(Double_t ax, Double_t bx, Double_t ay, Double_t by, Double_t epsrel=1.e-6)
Return Integral of a 2d function in range [ax,bx],[ay,by] with desired relative accuracy (default val...
virtual void SetTextFont(Font_t tfont=62)
Set the text font. 
TAxis * GetYaxis() const
Get y axis of the function. 
To draw Mathematical Formula. 
virtual void SetLineColor(Color_t lcolor)
Set the line color. 
void ChangeLabel(Int_t labNum=0, Double_t labAngle=-1., Double_t labSize=-1., Int_t labAlign=-1, Int_t labColor=-1, Int_t labFont=-1, TString labText="")
Define new text attributes for the label number "labNum". 
virtual void SetNpy(Int_t npy=100)
Set the number of points used to draw the function. 
virtual void SetPhi(Double_t phi=30)
void SetHistTopMargin(Double_t hmax=0.05)
A 2-Dim function with parameters. 
virtual void SetLabelSize(Float_t size=0.04)
Set size of axis labels The size is expressed in per cent of the pad width. 
virtual void SetTitleSize(Float_t size=0.04)
Set size of axis title The size is expressed in per cent of the pad width. 
virtual void Draw(Option_t *option="")
Draw this 3-D polyline with its current attributes. 
static constexpr double s
virtual void SetLineStyle(Style_t lstyle)
Set the line style. 
you should not use this method at all Int_t Int_t z
void SetOptStat(Int_t stat=1)
The type of information printed in the histogram statistics box can be selected via the parameter mod...
void SetOptTitle(Int_t tit=1)
virtual void SetTextColor(Color_t tcolor=1)
Set the text color. 
virtual void SetParameter(Int_t param, Double_t value)
virtual void SetTitle(const char *title="")
Set the title of the TNamed. 
TAxis * GetZaxis() const
Get z axis of the function. (In case this object is a TF2 or TF3)