Patrick,
I do not see a problem with the last bin in your example.
Which version are you using?
In case you use an old version, please upgrade your system.
Rene Brun
On Tue, 10 Feb
2004, Patrick SIZUN wrote:
> Hi,
>
> I face a problem when drawing a variable bin size histo in log scale.
> The last channel is not displayed correctly but is much larger than it should.
>
> Below is an example where I just took a script given in the roottalk forum and
> changed the minimum to show the phenomenon.
>
> Can some one help ?
>
> P. Sizun
>
> {
> const Int_t nbins = 100;
> Double_t xmin = 1e-3;
> Double_t xmax = 1e3;
> Double_t logxmin = TMath::log10(xmin);
> Double_t logxmax = TMath::log10(xmax);
> Double_t binwidth = (logxmax-logxmin)/nbins;
> Double_t xbins[nbins+1];
> xbins[0] = xmin;
> for (Int_t i=1;i<=nbins;i++) {
> xbins[i] = xmin + TMath::Power(10,logxmin+i*binwidth);
> }
> TH1F *h = new TH1F("h","hist with log x axis",nbins,xbins);
>
> Double_t x,xl;
> for (Int_t j=0;j<10000;j++) {
> xl = 0.5*(logxmin+logxmax) + 12*binwidth*gRandom->Gaus(0,1);
> x = xmin + TMath::Power(10,xl);
> h->Fill(x);
> }
> TCanvas *c1 = new TCanvas("c1");
> c1->SetLogx();
> h->SetMinimum(-200.0);
> h->Draw();
> }
>
>
>
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