TF3

*-*-*-*-*-*-*-*-*-*-*F3 default constructor*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*
*-*                  ======================

*-*-*-*-*-*-*F3 constructor using a formula definition*-*-*-*-*-*-*-*-*-*-*
*-*          =========================================
*-*
*-*  See TFormula constructor for explanation of the formula syntax.
*-*
*-*
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*-*-*-*-*-*-*F3 constructor using a pointer to an interpreted function*-*-*
*-*          =========================================================
*-*
*-*   npar is the number of free parameters used by the function
*-*
*-*  Creates a function of type C between xmin and xmax and ymin,ymax.
*-*  The function is defined with npar parameters
*-*  fcn must be a function of type:
*-*     Double_t fcn(Double_t *x, Double_t *params)
*-*
*-*  This constructor is called for functions of type C by CINT.
*-*
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*-*-*-*-*-*-*F3 constructor using a pointer to real function*-*-*-*-*-*-*-*
*-*          ===============================================
*-*
*-*   npar is the number of free parameters used by the function
*-*
*-*  For example, for a 3-dim function with 3 parameters, the user function
*-*      looks like:
*-*    Double_t fun1(Double_t *x, Double_t *par)
*-*        return par[0]*x[2] + par[1]*exp(par[2]*x[0]*x[1]);
*-*
*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*

 Operator =

*-*-*-*-*-*-*-*-*-*-*F3 default destructor*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*
*-*                  =====================

*-*-*-*-*-*-*-*-*-*-*Copy this F3 to a new F3*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*
*-*                  ========================

*-*-*-*-*-*-*-*-*-*-*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:
*-*
*-*
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*-*-*-*-*-*-*-*-*-*-*Draw this function with its current attributes*-*-*-*-*
*-*                  ==============================================

*-*-*-*-*-*-*-*-*-*-*Execute action corresponding to one event*-*-*-*
*-*                  =========================================
*-*  This member function is called when a F3 is clicked with the locator
*-*
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 Return the X, Y and Z values corresponding to the minimum value of the function
 on its range. To find the minimum on a subrange, use the SetRange() function first.
 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,fNpy and fNpz sub-ranges. If the function is "good"(or "bad"),
   these values can be changed by SetNpx(), SetNpy() and SetNpz() functions.
   Then, Minuit minimization is used with starting values found by the grid search

*-*-*-*-*-*Return 3 random numbers following this function shape*-*-*-*-*-*
*-*        =====================================================
*-*
*-*   The distribution contained in this TF3 function is integrated
*-*   over the cell contents.
*-*   It is normalized to 1.
*-*   Getting the three 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 * fNpz points.
*-*  If the function has sharp peaks, you should increase the number of
*-*  points (SetNpx, SetNpy, SetNpz) such that the peak is correctly tabulated
*-*  at several points.

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

 Get value corresponding to X in array of fSave values

 Return Integral of a 3d function in range [ax,bx],[ay,by],[az,bz]

 Return kTRUE is the point is inside the function range

*-*-*-*-*-*-*-*-*Paint this 3-D function with its current attributes*-*-*-*-*
*-*              ===================================================

 Set the function clipping box (for drawing) "off".

 Save values of function in array fSave

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

 Set the function clipping box (for drawing) "on" and define the clipping box.
 xclip, yclip and zclip is a point within the function range. All the
 function values having x<=xclip and y<=yclip and z>=zclip are clipped.

 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 TF3::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 TF3.

 Return x^nx * y^ny * z^nz moment of a 3d function in range [ax,bx],[ay,by],[az,bz]
   Author: Gene Van Buren <gene@bnl.gov>

 Return x^nx * y^ny * z^nz central moment of a 3d function in range [ax,bx],[ay,by],[az,bz]
   Author: Gene Van Buren <gene@bnl.gov>