Hi Andreas, Note that after doing: TH1F* hist1 = new TH1F(); tree->Draw("variable1>>hist1(10, 0, 10)", "", ""); There is NO relation being the object pointed to by the variable 'hist1' and the histogam drawn on the screen. The relation is done using the 'ROOT name' of the object and NOT the name of variable that point to it. Do either TH1F* hist1pointer = new TH1F("hist1name","hist1title",10,0,10); tree->Draw("variable1>>hist1", "", ""); or tree->Draw("variable1>>hist1(10, 0, 10)", "", ""); TH1F* hist1pointer = (TH1F*)gDirectory->Get("hist"); > gStyle->SetHistLineStyle(3); .. does not work By default, when an histogram is created by the TTree::Draw command, the graphical attributes are determined by the TTree. If the tree is retrieve from a file, thoses attributes are read from the file rather than gStyle. To force histogram and TTree which are read from a file to update their attribute using the current gStyle use: gROOT->ForceStyle(); So you can do either: tree->SetLineStyle(3); tree->Draw("variable1>>hist1(10, 0, 10)", "", ""); or gStyle->SetHistLineStyle(3); gROOT->ForceStyle(); tree->Draw("variable1>>hist1(10, 0, 10)", "", ""); or gStyle->SetHistLineStyle(3); TH1F* hist1pointer = new TH1F("hist1name","hist1title",10,0,10); tree->Draw("variable1>>hist1", "", ""); Cheers, Philippe. -----Original Message----- From: owner-roottalk@pcroot.cern.ch [mailto:owner-roottalk@pcroot.cern.ch]On Behalf Of Andreas Salzburger Sent: Friday, August 15, 2003 4:21 AM To: Roottalk Subject: [ROOT] TTree::Draw LineStyle Otptions Hi roottalkers, i think i have a simple question, but somehow i can't manage to do it: i try to compare to plots which i create from a tree, so first i create to histograms TH1F* hist1 = new TH1F(); TH1F* hist2 = new TH1F(); then i do the following: tree->Draw("variable1>>hist1(10, 0, 10)", "", ""); tree->Draw("variable2>>hist2(10, 0, 10)", "", "same"); works out fine, but then i wanted to draw one with a dashed line! neither does hist1->SetLineStyle(3); work, nor gStyle->SetHistLineStyle(3); anyway i'm reading a rootlogon.C script predefining my styles, but even if i insert gStyle->SetHistLineStyle(3); in the script, the LineStyle is solid. has anyone an idea how to solve that? thanks in advance, andreas p.s. echo $ROOTSYS /afs/cern.ch/sw/root/v3.05.04/rh73_gcc32/root
This archive was generated by hypermail 2b29 : Thu Jan 01 2004 - 17:50:14 MET