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.

 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"

 Draw formula between xmin,ymin and xmax,ymax.

 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.

 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>