Hi Pierre-Luc, A very expensive compromise. All the work is already done by TTree::Draw and TTreeFormula. Up to you to find your way extracting code from TTreeFormula. Rene Brun On Mon, 5 Aug 2002, Pierre-Luc Drouin wrote: > Hello, > > The SNO events are in an ASCII file. Both PAW NTuples and ROOT trees are > dumped in an ASCII file, and then used by QSNO to extract signal (people > that use PAW NTuples didn't want to convert in ROOT trees and vice-versa, > so it is the compromise). My class reads events in the ASCII file, > applies the cut and add it to a two-dimensions float array, this > information being given to another class after... If people want to define > a new cut, they add it to the dat file, and call the member function that > applies cut again. > > Pierre-Luc Drouin > SNO, Carleton University > > On Mon, 5 Aug 2002, Rene Brun wrote: > > > Pierre-Luc, > > > > Did you look at TTreeFormula? > > We use this class to make cuts in ROOT TTrees. > > What is the format of your SNO events? > > > > Rene Brun > > > > On Mon, 5 Aug 2002, Pierre-Luc Drouin wrote: > > > > > Hi, > > > > > > I'm working on a program that reads equations in a dat file and use them > > > to apply cuts on some SNO events. Users must be able to change cut > > > equations in the dat file without recompiling QSNO (SNO analysis > > > program). Cuts may combine more than 4 parameters, that's why I need an > > > equation interpreter that can interpret formulas with more than 4 > > > variables. > > > > > > Thank you! > > > > > > Pierre-Luc Drouin > > > SNO, Carleton University > > > > > > On Mon, 5 Aug 2002, Rene Brun wrote: > > > > > > > May be you should explain what you want to do ! > > > > Why don't you use CINT directly as an interpreter? > > > > > > > > The convention in TFormula is to use the letters x,y,z,t > > > > to identify the 1st,2nd,3rd,4th dimension in the expression. > > > > For sure we could use the 26 characters + upper case. > > > > I don't think this would be the right way to proceed. > > > > > > > > Rene Brun > > > > > > > > On Mon, 5 Aug 2002, Pierre-Luc Drouin wrote: > > > > > > > > > Hi, > > > > > > > > > > The problem I have is that I'm making a class that must be the most > > > > > flexible as possible, and it's possible that it needs more than 4 > > > > > variables (perhaps 10, or more). Is there a mean to do that using > > > > > TFormula? I mean, once an interpreter is able to interpret > > > > > complex equations like > > > > > TFormula is able to do, what does limit the number of variables? > > > > > > > > > > Thank you! > > > > > > > > > > Pierre-Luc Drouin > > > > > > > > > > On Mon, 5 Aug 2002, Rene Brun wrote: > > > > > > > > > > > Hi Pierre-Luc > > > > > > > > > > > > TFormula allows up to 4 dimensions. Example: > > > > > > root > TFormula f("f","x+y+z+t") > > > > > > root > double x[4] = {1,2,3,4} > > > > > > root > f.EvalPar(x) > > > > > > > > > > > > The current documentation indicates a max of 3 dimensions. > > > > > > I have updated the comments in the CVS version. > > > > > > > > > > > > Rene Brun > > > > > > > > > > > > On Mon, 5 Aug 2002, Pierre-Luc Drouin wrote: > > > > > > > > > > > > > Hello, > > > > > > > > > > > > > > I need an equation interpreter that can be used with more than 3 > > > > > > > variables. Is there a class that allows it in ROOT? > > > > > > > > > > > > > > Thank you! > > > > > > > > > > > > > > Pierre-Luc Drouin > > > > > > > > > > > > > > > > > > > > > > > > > > > >
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