Time axis is modified by Scale method in TH1

ROOT
1

Dear ROOTers
Using the ROOT 5.15.01 and 5.12/00f on Linux (sorry, not the latest one),
I found some strange feature in Scale method of TH1.
Please try the following core on your machine.

void timetest2() {
  TDatime sdate(2006, 05, 20, 00, 00, 00);
  gStyle->SetTimeOffset(sdate.Convert());

  TH1F *h = new TH1F("h", "", 86400, 0, 86400);
  for ( Int_t i = 1; i<86400>SetBinContent(i, 1);}
  h->GetXaxis()->SetTimeDisplay(1);
  h->GetXaxis()->SetTimeFormat("%y/%m/%d/%H:%M");
  
  TCanvas *c = new TCanvas("c", "", 50, 50, 900, 600);
  c->Divide(1, 2);
  c->cd(1);
  gPad->SetGridx();
  h->Draw();

  c->cd(2);
  TH1F *h2 = (TH1F*)h->Clone("h2");
  gPad->SetGridx();
  h2->Scale(0.5);
  h2->Draw();
}

The time axis in h2 is strange, extending to 2006/5/22 instead of 2006/5/21. Both time axis range should be the same.
In the macro, if I comment out h2->Scale(0.5), I can obtain
the correct time axis range in both h and h2.

please give me any idea.

I try the macro on Linux 2.6.18 of Fedora Core 6 with gcc 4.1.1

2

Your macro code has been corrupted.
Can you resend it but as an attachment.
Sometimes it does not work when you put it inline.

3

If you put inline code, always:
-select the option Code
-click the check box "Disable html in this post"
otherwise text involving arrows will be interpreted as html

Rene

4

I re-send only my macro.

void timetest2() {
  TDatime sdate(2006, 05, 20, 00, 00, 00);
  gStyle->SetTimeOffset(sdate.Convert());

  TH1F *h = new TH1F("h", "", 86400, 0, 86400);
  h->Sumw2();
  for ( Int_t i = 1; i <= 86400; i++ ) {
    h->SetBinContent(i, 1);
  }
  h->GetXaxis()->SetTimeDisplay(1);
  h->GetXaxis()->SetTimeFormat("%y/%m/%d/%H:%M");
  cout << sdate.GetDate() " " << sdate.GetTime() << endl;
  TCanvas *c = new TCanvas("c", "", 50, 50, 900, 600);
  c->Divide(1, 2);
  c->cd(1);
  gPad->SetGridx();
  h->Draw();

  c->cd(2);
  TH1F *h2 = (TH1F*)h->Clone("h2");
  gPad->SetGridx();
  h2->Scale(0.5);
  h2->Draw();
}
5

This is now fixed in the CVS head. Thanks to have reported it.