class TSelectorDraw: public TSelector

 Default selector constructor.

 Selector destructor.

 Called everytime a loop on the tree(s) starts.

 Delete internal buffers.

 Compile input variables and selection expression.

  varexp is an expression of the general form e1:e2:e3
    where e1,etc is a formula referencing a combination of the columns
  Example:
     varexp = x  simplest case: draw a 1-Dim distribution of column named x
            = sqrt(x)         : draw distribution of sqrt(x)
            = x*y/z
            = y:sqrt(x) 2-Dim dsitribution of y versus sqrt(x)

  selection is an expression with a combination of the columns
  Example:
      selection = "x<y && sqrt(z)>3.2"
       in a selection all the C++ operators are authorized

  Return kFALSE if any of the variable is not compilable.

 Return the last values corresponding to the i-th component
 of the formula being processed (where the component are ':' separated).
 The actual number of entries is:
     GetSelectedRows() % tree->GetEstimate()
 Note GetSelectedRows currently returns the actual number of values plotted
 and thus if the formula contains arrays, this number might be greater than
 the number of entries in the trees.
 By default TTree::Draw creates the arrays obtained
    with all GetVal and GetW with a length corresponding to the
    parameter fEstimate. By default fEstimate=10000 and can be modified
    via TTree::SetEstimate. A possible recipee is to do
       tree->SetEstimate(tree->GetEntries());
    You must call SetEstimate if the expected number of selected rows
    is greater than 10000.
 See TTree::Draw for additional details.

 Return the TTreeFormula corresponding to the i-th component
 of the request formula (where the component are ':' separated).

 Initialization of the primitive type arrays if the new size is bigger than the available space.

 Build Index array for names in varexp.
 This will allocated a C style array of TString and Ints

 This function is called at the first entry of a new tree in a chain.

 Called in the entry loop for all entries accepted by Select.

 Called in the entry loop for all entries accepted by Select.
 Complex case with multiplicity.

 Called in the entry loop for all entries accepted by Select.
 Case where the only variable returns an object (or pointer to).

 Set number of entries to estimate variable limits.

 Execute action for object obj fNfill times.

 Estimate limits for 1-D, 2-D or 3-D objects.

 Called at the end of a loop on a TTree.

 See TSelectorDraw::GetVar

 See TSelectorDraw::GetVar

 See TSelectorDraw::GetVar

 See TSelectorDraw::GetVar

 See TSelectorDraw::GetVal

 See TSelectorDraw::GetVal

 See TSelectorDraw::GetVal

 See TSelectorDraw::GetVal