TFoam

 Default constructor for streamer, user should not use it.

 User constructor, to be employed by the user

 Default destructor
  cout<<" DESTRUCTOR entered "<<endl;

 Copy Constructor  NOT IMPLEMENTED (NEVER USED)

 Basic initialization of FOAM invoked by the user. Mandatory!
 ============================================================
 This method starts the process of the cell build-up.
 User must invoke Initialize with two arguments or Initialize without arguments.
 This is done BEFORE generating first MC event and AFTER allocating FOAM object
 and reseting (optionally) its internal parameters/switches.
 The overall operational scheme of the FOAM is the following:

 This method invokes several other methods:
 ==========================================
 InitCells initializes memory storage for cells and begins exploration process
 from the root cell. The empty cells are allocated/filled using  CellFill.
 The procedure Grow which loops over cells, picks up the cell with the biggest
 ``driver integral'', see Comp. Phys. Commun. 152 152 (2003) 55 for explanations,
 with the help of PeekMax procedure. The chosen cell is split using Divide.
 Subsequently, the procedure Explore called by the Divide
 (and by InitCells for the root cell) does the most important
 job in the FOAM object build-up: it performs a small MC run for each
 newly allocated daughter cell.
 Explore calculates how profitable the future split of the cell will be
 and defines the optimal cell division geometry with the help of Carver or Varedu
 procedures, for maximum weight or variance optimization respectively.
 All essential results of the exploration are written into
 the explored cell object. At the very end of the foam build-up,
 Finally, MakeActiveList is invoked to create a list of pointers to
 all active cells, for the purpose of the quick access during the MC generation.
 The procedure Explore employs MakeAlpha to generate random coordinates
 inside a given cell with the uniform distribution.
 The above sequence of the procedure calls is depicted in the following figure:

 Basic initialization of FOAM invoked by the user.
 IMPORTANT: Random number generator and the distribution object has to be
 provided using SetPseRan and SetRho prior to invoking this initializator!

 Internal subprogram used by Initialize.
 It initializes "root part" of the FOAM of the tree of cells.

 Internal subprogram used by Initialize.
 It initializes content of the newly allocated active cell.

 Internal subprogram used by Initialize.
 It explores newly defined cell with help of special short MC sampling.
 As a result, estimates of true and drive volume is defined/determined
 Average and dispersion of the weight distribution will is found along
 each edge and the best edge (minimum dispersion, best maximum weight)
 is memorized for future use.
 The optimal division point for eventual future cell division is
 determined/recorded. Recorded are also minimum and maximum weight etc.
 The volume estimate in all (inactive) parent cells is updated.
 Note that links to parents and initial volume = 1/2 parent has to be
 already defined prior to calling this routine.

 Internal subrogram used by Initialize.
 In determines the best edge candidate and the position of the cell division plane
 in case of the variance reduction for future cell division,
 using results of the MC exploration run stored in fHistEdg

 Internal subrogram used by Initialize.
 Determines the best edge-candidate and the position of the division plane
 for the future cell division, in the case of the optimization of the maximum weight.
 It exploits results of the cell MC exploration run stored in fHistEdg.

 Internal subrogram used by Initialize.
 Provides random vector Alpha  0< Alpha(i) < 1

 Internal subrogram used by Initialize.
 It grow new cells by the binary division process.

 Internal subprogram used by Initialize.
 It finds cell with maximal driver integral for the purpose of the division.

 Internal subrogram used by Initialize.
 It divides cell iCell into two daughter cells.
 The iCell is retained and tagged as inactive, daughter cells are appended
 at the end of the buffer.
 New vertex is added to list of vertices.
 List of active cells is updated, iCell removed, two daughters added
 and their properties set with help of MC sampling (TFoam_Explore)
 Returns Code RC=-1 of buffer limit is reached,  fLastCe=fnBuf.

 Internal subrogram used by Initialize.
 It finds out number of active cells fNoAct,
 creates list of active cell fCellsAct and primary cumulative fPrimAcu.
 They are used during the MC generation to choose randomly an active cell.

 User may optionally reset random number generator using this method
 Usually it is done when FOAM object is restored from the disk.
 IMPORTANT: this method deletes existing  random number generator registered in the FOAM object.
 In particular such an object is created by the streamer during the disk-read operation.

 User may use this method to set (register) random number generator used by
 the given instance of the FOAM event generator. Note that single r.n. generator
 may serve several FOAM objects.

 User may optionally reset the distribution using this method
 Usually it is done when FOAM object is restored from the disk.
 IMPORTANT: this method deletes existing  distribution object registered in the FOAM object.
 In particular such an object is created by the streamer diring the disk-read operation.
 This method is used only in very special cases, because the distribution in most cases
 should be "owned" by the FOAM object and should not be replaced by another one after initialization.

 User may use this to set pointer to the global function (not descending
 from TFoamIntegrand) serving as a distribution for FOAM.
 It is useful for simple interactive applications.
 Note that persistency for FOAM object will not work in the case of such
 a distribution.

 Internal subprogram.
 Evaluates distribution to be generated.

 Internal subprogram.
 Return randomly chosen active cell with probability equal to its
 contribution into total driver integral using interpolation search.

 User subprogram.
 It generates randomly point/vector according to user-defined distribution.
 Prior initialization with help of Initialize() is mandatory.
 Generated MC point/vector is available using GetMCvect and the MC weight with GetMCwt.
 MC point is generated with wt=1 or with variable weight, see OptRej switch.

 User may get generated MC point/vector with help of this method

 User may get weight MC weight using this method

 User may get weight MC weight using this method

 User subprogram which generates MC event and returns MC weight

 User subprogram.
 It provides the value of the integral calculated from the averages of the MC run
 May be called after (or during) the MC run.

 User subprogram.
 It returns NORMALIZATION integral to be combined with the average weights
 and content of the histograms in order to get proper absolute normalization
 of the integrand and distributions.
 It can be called after initialization, before or during the MC run.

 May be called optionally after the MC run.
 Returns various parameters of the MC weight for efficiency evaluation

 May be called optionally by the user after the MC run.
 It provides normalization and also prints some information/statistics on the MC run.

 This can be called before Initialize, after setting kDim
 It defines which variables are excluded in the process of the cell division.
 For example 'FoamX->SetInhiDiv(1, 1);' inhibits division of y-variable.
 The resulting map of cells in 2-dim. case will look as follows:

 This should be called before Initialize, after setting  kDim
 It predefines values of the cell division for certain variable iDim.
 For example setting 3 predefined division lines using:
     xDiv[0]=0.30; xDiv[1]=0.40; xDiv[2]=0.65;
     FoamX->SetXdivPRD(0,3,xDiv);
 results in the following 2-dim. pattern of the cells:

  User utility, miscellaneous and debug.
  Checks all pointers in the tree of cells. This is useful autodiagnostic.
  level=0, no printout, failures causes STOP
  level=1, printout, failures lead to WARNINGS only

 Prints geometry of ALL cells of the FOAM

 Debugging tool which plots 2-dimensional cells as rectangles
 in C++ format readable for root

 Void function for backward compatibility

 Getters and Setters

 Getters and Setters

 Debug