To use the [cut] option in Projections, you must use a recent version like
4.01/04
Rene Brun
ddas@veccal.ernet.in wrote:
>
> Hello
> does anybody know how to project subrange of a 2D histogram.
> I tried using TCutG but somehow could not get the result.
> I wanted to change by Projection X from value1 to value2 and then plot that part only.
> Also if somebody can explain what this SetPoint means.
>
> Example:
>
> {
> TCanvas *c = new TCanvas("c","example",0,0,700,600);
> c->Divide(1,2);
>
> TCutG *gcut = new TCutG("gcut",8);
> gcut->SetPoint(0,-0.646552,0.932203);
> gcut->SetPoint(1,-1.26437,0.105932);
> gcut->SetPoint(2,-0.574713,-1.10169);
> gcut->SetPoint(3,0.948276,-0.338983);
> gcut->SetPoint(4,1.07759,0.720339);
> gcut->SetPoint(5,-0.316092,-0.0847458);
> gcut->SetPoint(6,-0.45977,0.402542);
> gcut->SetPoint(7,-0.646552,0.932203);
>
> TFile f("hsimple.root")
> TH2F *hpxpy = (TH2F*)f.Get("hpxpy");
> TH1D *hppx = hpxpy->ProjectionX("",1,40,"[gcut]");
>
> c->cd(1);
> hpxpy->SetFillColor(kBlue);
> hpxpy->DrawCopy("box");
> hpxpy->SetFillColor(kRed);
> hpxpy->Draw("same box [gcut]");
>
> c->cd(2);
> hppx->Draw();
> }
>
> thanks again
> debasish.
>
>
This archive was generated by hypermail 2b29 : Sun Jan 02 2005 - 05:50:10 MET