This patch introduces a new special function in TTreeFormula Sum$
described as follow:

//  Sum$(formula): return the sum of the value of the elements of the
//  formula given  as a parameter.  For example the mean for all the
//  elements in  one entry can be calculated with:
//                Sum$(formula)/Length$(formula)

The idea comes from http://root.cern.ch/phpBB2/viewtopic.php?p=6943


git-svn-id: http://root.cern.ch/svn/root/trunk@11629 27541ba8-7e3a-0410-8455-c3a389f83636

This patch implements support for the accessing the collection object in
TTreeFormula:

//     Accessing collection objects
//     ============================
//
//  TTree::Draw default's handling of collections is to assume that any
//  request on a collection pertain to it content.  For example, if fTracks
//  is a collection of Track objects, the following:
//      tree->Draw("event.fTracks.fPx");
//  will plot the value of fPx for each Track objects inside the collection.
//  Also
//     tree->Draw("event.fTracks.size()");
//  would plot the result of the member function Track::size() for each
//  Track object inside the collection.
//  To access information about the collection itself, TTree::Draw support
//  the '@' notation.  If a variable which points to a collection is
prefixed
//  or postfixed with '@', the next part of the expression will pertain to
//  the collection object.  For example:
//     tree->Draw("event.@fTracks.size()");
//  will plot the size of the collection refered to by fTracks (i.e the
number
//  of Track objects).


git-svn-id: http://root.cern.ch/svn/root/trunk@11309 27541ba8-7e3a-0410-8455-c3a389f83636

This patch extends the notion of TTree variable aliases to allow
them to be used as part of single data name.

For example, you can now do:
    tree->SetAlias("theGoodTrack","event.fTracks[3]");
    tree->Draw("theGoodTrack.fPx"); // same as "event.fTracks[3].fPx"

This patch includes a little clean-up in TTreeFormula::DefinedVariable
to better separate the different phases of the parsing (dimension requests,
leaf finding and exploration into the user class).

This patch also includes an update to DrawTest to test for the new alias
feature and in case of failure to print the corresponding Draw command.


git-svn-id: http://root.cern.ch/svn/root/trunk@11141 27541ba8-7e3a-0410-8455-c3a389f83636

This patch insures that TFormula does modify the 'strings' that are embedded
in an expression.


git-svn-id: http://root.cern.ch/svn/root/trunk@10985 27541ba8-7e3a-0410-8455-c3a389f83636

The following patch
	insure a bool (UChar_t) is considered as an integer by TTreeFormula
	add a test for Bool.
        Remove a warning on linux for TFormLeafInfo


git-svn-id: http://root.cern.ch/svn/root/trunk@10950 27541ba8-7e3a-0410-8455-c3a389f83636

        Add support for the boolean optimization in TFormula::GetExpFormula

        Prevent TTree::Scan from printing random value for invalid formulas

        Add a new TTreeFormula special function:

      Alt$(primary,alternate) : return the value of "primary" if it is available
                    for the current iteration otherwise return the value of "alternate".
                    For example, with arr1[3] and arr2[2]
      tree->Draw("arr1-Alt$(arr2,0)");
                 will draw arr[0]+arr2[0] ; arr[1]+arr2[1] and arr[1]+0
                    Or with a variable size array arr3
       tree->Draw("Alt$(arr3[0],0)+Alt$(arr3[1],0)+Alt$(arr3[2],0)");
                    will draw the sum arr3 for the index 0 to min(2,actual_size_of_arr3-1)
                    As a comparison
       tree->Draw("arr3[0]+arr3[1]+arr3[2]");
                    will draw the sum arr3 for the index 0 to 2 only if the
                    actual_size_of_arr3 is greater or equal to 3.
                    Note that the array in 'primary' is flatened/linearilized thus using
                    Alt$ with multi-dimensional arrays of different dimensions in unlikely
                    to yield the expected results.  To visualize a bit more what elements
                    would be matched by TTree::Draw, TTree::Scan can be used:
       tree->Scan("arr1:Alt$(arr2,0)");
                    will print on one line the value of arr1 and (arr2,0) that will be
                    matched by
       tree->Draw("arr1-Alt$(arr2,0)");


git-svn-id: http://root.cern.ch/svn/root/trunk@7780 27541ba8-7e3a-0410-8455-c3a389f83636

Warning: wrong member access operator '->' FILE:dt_MakeRef.C LINE:172
Warning: wrong member access operator '->' FILE:dt_MakeRef.C LINE:250


git-svn-id: http://root.cern.ch/svn/root/trunk@7093 27541ba8-7e3a-0410-8455-c3a389f83636

The following patch implements TTree variable alias.

To use them:
        mytree->SetAlias("mult","fPx*fPy");
        mytree->Draw("mult");

Note that the aliases have been added to the TTree object so that they can be persistent (with the tree) if you choose.

Also note that the alias are not checked for validity until they are used in a Draw or Scan command.

Existing alias are silently replaced.

The new functions are:
        TTree::SetAlias
        TTree::GetAlias
        TChain::GetAlias
        TTree::GetListOfAliases

This patch also adds operator= for TFormula, TF1, TF2, TF3 (it calls the respective Copy member functions).  It makes TTreeFormula::operator= private (Copy has not been implemented yet).

Also some of the TFormula and TTreeFormula codes (those stored in fOper) has been aliased to enums (this renders the code is little bit more readable and searchable).

TFormula and TTreeFormula have been updated to handle strings in a more flexible (and for TTreeFormula to be able to return them).


git-svn-id: http://root.cern.ch/svn/root/trunk@6805 27541ba8-7e3a-0410-8455-c3a389f83636

DrawTest was updated to test calling a global function.


git-svn-id: http://root.cern.ch/svn/root/trunk@6715 27541ba8-7e3a-0410-8455-c3a389f83636

This patch adds systematic test for the ability of TTree::Draw to draw TBits objects.
It also fixes all the bug discovered during the tests.
It also adds a test for split level 2.


git-svn-id: http://root.cern.ch/svn/root/trunk@6011 27541ba8-7e3a-0410-8455-c3a389f83636

DrawTest now has a test of drawing an array values with a scalar weight.


git-svn-id: http://root.cern.ch/svn/root/trunk@5448 27541ba8-7e3a-0410-8455-c3a389f83636

This update to drawtest does the following:
        start moving toward using makefile
        reduce the text printed while running
        reduce the time as much as possible


git-svn-id: http://root.cern.ch/svn/root/trunk@5063 27541ba8-7e3a-0410-8455-c3a389f83636

array inside a TClonesArray when the TClonesArray is not split.
It also adds a test for reading variable size array inside a TClonesArray.
It also fixes a problem recently mentioned on roottalk where the formula
for not properly reading variable size array when the
variable size was indexed more there was more than one variable in the formula.


git-svn-id: http://root.cern.ch/svn/root/trunk@5037 27541ba8-7e3a-0410-8455-c3a389f83636

They are now considered by default as an array of numbers.  However if
they are used with an operator== or an operator!= and if the second argument
is also a string, the strcmp function will be used.  In addition, a direct call
of the function strstr is allowed.   The checks and error messages have been
improved for both the operator and strstr.
This update also corrects the problem where an expression was drawn multiple
times when using a fixed length array in string comparaison.


git-svn-id: http://root.cern.ch/svn/root/trunk@3390 27541ba8-7e3a-0410-8455-c3a389f83636

git-svn-id: http://root.cern.ch/svn/root/trunk@2562 27541ba8-7e3a-0410-8455-c3a389f83636

git-svn-id: http://root.cern.ch/svn/root/trunk@2554 27541ba8-7e3a-0410-8455-c3a389f83636

To run the test, execute DrawTest.sh.


git-svn-id: http://root.cern.ch/svn/root/trunk@2531 27541ba8-7e3a-0410-8455-c3a389f83636