>>>>>>>>> now I included the test program (sorry!) Dear rooters, I have encountered the following "unexpected" beaviour of a TH1F histogram: I create a TH1F object and fill it with a set of (x,y) data points, the y coordinate being used "as a weight". I find that, as long as the minimum among the y values is negative, the vertical axis range is automatically set centered on the y values Instead, if the minimum among the y values is positive (no matter how big it is), the vertical axis first value is always set to 0. !! Below I pasted my test program, just try to switch OffSet between +10. and -10. Is this the way it is supposed to work? ...or am I missing something ?? How I can have the vertical range centered on y values also in the second case?? Thank you, Irene >>>>>>>>>>>>>>>>> test program void test_range() { TCanvas *c1 = new TCanvas("c1","This is a TEST",600,400); TH1F *h1 = new TH1F("h1","my histogram",100,0.,100.); Int_t i; Float_t OffSet = +10.; // -10. for (i=0;i<100;i++) h1->Fill(float(i), OffSet + gRandom->Gaus(0,1)); h1->Draw(); c1->Update(); }
This archive was generated by hypermail 2b29 : Sat Jan 04 2003 - 23:51:12 MET