just a follow up: for some reason 21 is a threshold value - for *any*
integer nsamples > 21 macro below displays ntuple incorrectly. -pasha
Glen R. Salo writes:
> The macro below demonstrates the problem that I have been having with ntuples.
> When I run the macro on my machine (Linux 2.0.36, 2.21.08) I get a histogram
> displayed with the ranges going from -21 to -15. However, according to
> GetMaximum and GetMinimum, the X range should really be from -20.5 to 20.5. Why
> is the X axis set up incorrectly?
>
> Interestingly, if I change nsamples to a smaller number, say 21, everything
> works as expected.
>
> Thanks for your help.
>
> Glen
>
> {
>
> gROOT->Reset();
>
> TNtuple *n = new TNtuple("ntuple","RSphere attachment data",
> "xs:ys:zs:xe:ye:ze");
>
> Float_t xs, ys, zs;
> Float_t start, delt=1.;
>
> Int_t nsamples = 41;
>
> start = -nsamples*delt/2.;
>
> for (Int_t i=0; i<nsamples+1; i++) {
> for (Int_t j=0; j<nsamples+1; j++) {
> for (Int_t k=0; k<nsamples+1; k++) {
>
> xs = start + i*delt;
> ys = start + j*delt;
> zs = start + k*delt;
>
> n->Fill(xs,ys,zs,i,j,k);
>
> }
> }
> }
>
> printf("min = %f\n",n->GetMinimum("xs"));
> printf("max = %f\n",n->GetMaximum("xs"));
> n->Draw("xs");
>
> }
>
>
>
> *********************************************************************
>
> Glen R. Salo g.r.salo@ieee.org
> Mission Research Corporation (937)429-9261 Ext. 119
> 3975 Research Boulevard (937)429-2625 Fax
> Dayton, Ohio 45430-2108
>
> *********************************************************************
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