TAxis:SetTimeOffset

ROOT
1

Hi,
I would like to use the display time function of TAxis.
I noticed that the documentation says that dates should not be before 1995.
Nevertheless avoiding the use of TDatime makes it possible to have dates as early as 1970.
Is there a way to have dates earlier than 1970? Using negative time offsets makes root crash on my windows (VC10 version 5.30/00, win32).
I attached a very simple modification of timeonaxis2.C to illustrate the point. The axis should start at 1/1/1950.

Thanks for your help.

Best regards,
Michael Heldmann

[code]void timeonaxis_mod() {
// Define the time offset as 0 = 1/1/1970
//Author: Olivier Couet, Modidified: Michael Heldmann

gStyle->SetTimeOffset(0);

TH1F * h1 = new TH1F(“h1”,“test”,100,0,100000000);

TRandom r;
for (Int_t i=0;i<30000;i++) {
Double_t noise = r.Gaus(50000000,0.1*(100000000));
h1->Fill(noise);
}

h1->GetXaxis()->SetTimeDisplay(1);
h1->GetXaxis()->SetLabelSize(0.03);
h1->GetXaxis()->SetTimeFormat("%Y/%m");
h1->Draw();
}[/code]

2

I do not understand why you say:

There is nothing related to this date in your macro.

3

Sorry, I did not really explain myself.
I would like the axis to start 1/1/1950.
But since I already use
gStyle->SetTimeOffset(0);
and the axis start 1970 I would like to know what I could do to make it start 1950.
I tried negative values like
gStyle->SetTimeOffset(-10000);
but this crashes root at least on my windows installation (latest pro version precompied).

So my question is if there is any way to achieve an axis which starts 1950 (or say before 1970).

Michael

4

I tried a few things. But I am afraid there is no way to do that.