Hi,
TTree::Fit returns the number of Tree entries used by the fit.
To access the result of teh fit, you have two possibilities
option 1: you are interested by the result histogram and the fit function
=========================================================================
tree->Fit("gaus","leaf");
TH1F *htemp = (TH1F*)gDirectory->Get("htemp");
TF1 *f1 = (TF1*)htemp->GetFunction("gaus");
f1->GetParameter(0);
option 2: you are interested only by the fit function
=====================================================
tree->Fit("gaus","leaf");
TF1 *f1 = (TF1*)gROOT->GetFunction("gaus");
f1->GetParameter(0);
Rene Brun
On Tue, 13 Aug 2002, Takefumi SORA wrote:
> Hi,Rooters
>
> I want to fit "Leaf" and get its parameter.
> This is my program.
>
> TFile *f = new TFile("381run.root");
> TTree *tree = (TTree*)f.Get("tree");
> tree->Fit("gaus","leaf");
> TF1 *fit0 = tree->Fit("gaus","leaf");
> Double_t pedestal0 = fit0->GetParameter(1);
> cout << pedestal0 << endl;
>
> Executing it, returned the error message.
> Error: Incorrect assignment to fit0, wrong type 'Int_t'
>
> How can I avoid the trouble ?
>
> --
> Takefumi SORA <tak-sora@bg7.so-net.ne.jp>
>
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