class TF2: public TF1

F2 default constructor*-*-*-*-*-*-
*-*                  ======================

 F2 constructor using a formula definition

  See TFormula constructor for explanation of the formula syntax.

  if formula has the form "fffffff;xxxx;yyyy", it is assumed that
  the formula string is "fffffff" and "xxxx" and "yyyy" are the
  titles for the X and Y axis respectively.

-*-*F2 constructor using a pointer to a compiled function
*-*          =====================================================
-
*-*   npar is the number of free parameters used by the function
-
*-*   This constructor creates a function of type C when invoked
*-*   with the normal C++ compiler.
-
*-* WARNING! A function created with this constructor cannot be Cloned.
-
-

-*-*F2 constructor using a pointer to a compiled function
*-*          =====================================================
-
*-*   npar is the number of free parameters used by the function
-
*-*   This constructor creates a function of type C when invoked
*-*   with the normal C++ compiler.
-
*-* WARNING! A function created with this constructor cannot be Cloned.
-
-

*-*-*-*-*-*-*F2 constructor using a ParamFunctor,
*-*          a functor class implementing operator() (double *, double *)
-
*-*   npar is the number of free parameters used by the function
-
*-* WARNING! A function created with this constructor cannot be Cloned.
-

 Operator =

F2 default destructor*-*-*-*-*-*-
*-*                  =====================

 Copy constructor.

Copy this F2 to a new F2*-*-*-*-*-
*-*                  ========================

-*-*-*-*-*-*Compute distance from point px,py to a function
*-*                  ===============================================
*-*  Compute the closest distance of approach from point px,py to this function.
*-*  The distance is computed in pixels units.
-
*-*  Algorithm:
-
-
*

-*-*-*-*-*-*Draw this function with its current attributes
*-*                  ==============================================
*-* NB. You must use DrawCopy if you want to draw several times the same
*-*     function in the current canvas.
*

-*-*-*-*-*Draw a copy of this function with its current attributes
*-*            ========================================================
-
*-*  This function MUST be used instead of Draw when you want to draw
*-*  the same function with different parameters settings in the same canvas.
-
*-* Possible option values are:
*-*   "SAME"  superimpose on top of existing picture
*-*   "L"     connect all computed points with a straight line
*-*   "C"     connect all computed points with a smooth curve.
-
*-* Note that the default value is "F". Therefore to draw on top
*-* of an existing picture, specify option "SL"
-
*

-*-*-*-*-*-*-*Execute action corresponding to one event
*-*                  =========================================
*-*  This member function is called when a F2 is clicked with the locator
-
*

Return contour values into array levels*-*-
*-*            =======================================
-
*-*  The number of contour levels can be returned by getContourLevel
-
*

Return the number of contour levels*-*-*-*-*-
*-*            ===================================

 return minimum/maximum value of the function
 To find the minimum on a range, first set this range via the SetRange function
 If a vector x of coordinate is passed it will be used as starting point for the minimum.
 In addition on exit x will contain the coordinate values at the minimuma
 If x is NULL or x is inifinity or NaN, first, a grid search is performed to find the initial estimate of the
 minimum location. The range of the function is divided into fNpx and fNpy
 sub-ranges. If the function is "good" (or "bad"), these values can be changed
 by SetNpx and SetNpy functions
 Then, a minimization is used with starting values found by the grid search
 The minimizer algorithm used (by default Minuit) can be changed by callinga
  ROOT::Math::Minimizer::SetDefaultMinimizerType("..")
 Other option for the minimizer can be set using the static method of the MinimizerOptions class

 Compute the X and Y values corresponding to the minimum value of the function
 Return the minimum value of the function
 To find the minimum on a range, first set this range via the SetRange function
 Method:
   First, a grid search is performed to find the initial estimate of the
   minimum location. The range of the function is divided into fNpx and fNpy
   sub-ranges. If the function is "good" (or "bad"), these values can be changed
   by SetNpx and SetNpy functions
   Then, a minimization is used with starting values found by the grid search
   The minimizer algorithm used (by default Minuit) can be changed by callinga
   ROOT::Math::Minimizer::SetDefaultMinimizerType("..")
   Other option for the minimizer can be set using the static method of the MinimizerOptions class

   Note that this method will always do first a grid search in contrast to GetMinimum

 Compute the X and Y values corresponding to the maximum value of the function
 Return the maximum value of the function
  See TF2::GetMinimumXY

 return minimum/maximum value of the function
 To find the minimum on a range, first set this range via the SetRange function
 If a vector x of coordinate is passed it will be used as starting point for the minimum.
 In addition on exit x will contain the coordinate values at the minimuma
 If x is NULL or x is inifinity or NaN, first, a grid search is performed to find the initial estimate of the
 minimum location. The range of the function is divided into fNpx and fNpy
 sub-ranges. If the function is "good" (or "bad"), these values can be changed
 by SetNpx and SetNpy functions
 Then, a minimization is used with starting values found by the grid search
 The minimizer algorithm used (by default Minuit) can be changed by callinga
  ROOT::Math::Minimizer::SetDefaultMinimizerType("..")
 Other option for the minimizer can be set using the static method of the MinimizerOptions class

 return maximum value of the function
 See TF2::GetMinimum

   Redefines TObject::GetObjectInfo.
   Displays the function value
   corresponding to cursor position px,py

Return a random number following this function shape*-
*-*        ====================================================
-

Return a random number following this function shape*-
*-*        ====================================================
-

Return 2 random numbers following this function shape
*-*        =====================================================
-
*-*   The distribution contained in this TF2 function is integrated
*-*   over the cell contents.
*-*   It is normalized to 1.
*-*   Getting the two random numbers implies:
*-*     - Generating a random number between 0 and 1 (say r1)
*-*     - Look in which cell in the normalized integral r1 corresponds to
*-*     - make a linear interpolation in the returned cell
-
-
*-*  IMPORTANT NOTE
*-*  The integral of the function is computed at fNpx * fNpy points.
*-*  If the function has sharp peaks, you should increase the number of
*-*  points (SetNpx, SetNpy) such that the peak is correctly tabulated
*-*  at several points.

Return range of a 2-D function*-*-
*-*                  ==============================

Return range of function*-*-*-*-
*-*                  ========================

 Get value corresponding to X in array of fSave values

 Return Integral of a 2d function in range [ax,bx],[ay,by]
 with desired relative accuracy (default value of eps is 1.e-9)

 Return kTRUE is the point is inside the function range

 Create a histogram from function.
 always created it, even if it is already existing

-*-*-*-*Paint this 2-D function with its current attributes
*-*              ===================================================

 Save values of function in array fSave

 Save primitive as a C++ statement(s) on output stream out

Set the number and values of contour levels*-
*-*            ===========================================

  By default the number of contour levels is set to 20.

  if argument levels = 0 or missing, equidistant contours are computed

Set value for one contour level*-
*-*                  ===============================

 Set the number of points used to draw the function

 The default number of points along x is 30 for 2-d/3-d functions.
 You can increase this value to get a better resolution when drawing
 pictures with sharp peaks or to get a better result when using TF2::GetRandom2
 the minimum number of points is 4, the maximum is 10000 for 2-d/3-d functions

-*-*Initialize the upper and lower bounds to draw the function
*-*        ==========================================================

 Stream an object of class TF2.

 Return x^nx * y^ny moment of a 2d function in range [ax,bx],[ay,by]
   Author: Gene Van Buren <gene@bnl.gov>

 Return x^nx * y^ny central moment of a 2d function in range [ax,bx],[ay,by]
   Author: Gene Van Buren <gene@bnl.gov>

virtual void     DrawF2(const char *formula, Double_t xmin, Double_t xmax, Double_t ymin, Double_t ymax, Option_t *option="");