Pierre-Luc,
This was difficult to guess from your first and second mail ::)
do f2->Print() and look at the fExpr[0],[1], etc
fExp contains an internal digested version of the expression.
>From this, it is theoretically possible to rebuild
the expanded formula. There is no API do do this.
If you implement it, let me know.
Rene Brun
On Thu, 12
Jun 2003, Pierre-Luc Drouin wrote:
> Suppose I do
>
> TFormula* f1 = new TFormula("f1","x+y");
> TFormula f2("f2","f1+2") ;
> delete f1;
>
> f2.GetTitle() doesn't return "x+y+2". It returns "f1+2"
>
> I want to get "x+y+2" even if f1 is deleted. Since the formula is
> implicitly stored in f2 member variables (I'm able to Eval() even when f1
> is deleted), I should be able to retrieve it
>
> Thank you
>
> Pierre-Luc Drouin
>
>
> On Thu, 12 Jun 2003, Rene Brun wrote:
>
> > Pierre-Luc,
> >
> > same answer as before. A TF1 is a TFormula. If you have
> > TF1 f("f:,"sin(x)/x",0,10);
> > f.GetTitle() returns "sin(x)/x"
> >
> > Rene Brun
> >
> > On Thu, 12 Jun
> > 2003, Pierre-Luc Drouin wrote:
> >
> > > Hi,
> > >
> > > My question was not very clear... sorry
> > >
> > > I've in a ROOT file a TF1 object that has been created using an user
> > > defined TFormula. I mean that the formula of the TF1 object
> > > (TNamed::fTitle) contains the TNamed::fName of an user define TFormula
> > > object. This TF1 object has been compiled and has been written in a ROOT
> > > file. Now I have to open the ROOT file, load the TF1 object and retrieve
> > > its
> > > formula. The formula is stored in the TFormula object tables of the TF1
> > > object and the TNamed::fTitle member variable contains the TFormula
> > > object name (this TFormula object doesn't exist anymore because only the
> > > TF1 object is contained in the ROOT file).
> > >
> > > I want to get the mathematical expression of the function contained in the
> > > TF1 object, expression that doesn't depend on a TFormula object name. It's
> > > not a problem if this expression is different from the original expression
> > > (when the TF1 object has been created the first time), I just want it to
> > > be equivalent. I want to apply a scaling factor and some complexe cuts on
> > > the TF1
> > > object, so it's essential to retrieve the expression.
> > >
> > > Thank you!
> > >
> > > Pierre-Luc Drouin
> > >
> > > On Thu, 12 Jun 2003, Rene Brun wrote:
> > >
> > > > Hi Pierre-Luc,
> > > >
> > > > TFormula is a TNamed. If you have TFormula* f, do
> > > > f->GetTitle();
> > > >
> > > > Rene Brun
> > > >
> > > > On Thu, 12 Jun 2003,
> > > > Pierre-Luc Drouin wrote:
> > > >
> > > > > Hi,
> > > > >
> > > > > How can I retrieve the formula string from a TFormula instance if
> > > > > SetTitle() has been called to change the default title by something else?
> > > > >
> > > > > Must ROOT users not call SetTitle() with a non mathematical string?
> > > > >
> > > > > Is it possible to retrieve a formula string from TFormula object tables?
> > > > >
> > > > > Thank you!
> > > > >
> > > > > Pierre-Luc Drouin
> > > > >
> > > >
> > >
> >
>
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