Tadeusz Pytlos wrote: > > Hello Rooters, > I can't understand how to operate on histograms. > I just want to receive h14=h4, but I solved it > in quite unelegant way. Would you tell me what is wrong in my macro? > I reckon that operating togeher on objects and pointers > causes a complicating notation. I wish there was no pointers at all > or there were hidden pointers, but I understand that there are many > benefits of pointers... > Best wishes, > Tadeusz > > { > ////////////////////////////////////////////////////////// > // This file has been automatically generated > // (Mon Nov 24 12:46:19 1997 by ROOT version 1.03/07) > // from TTree kas/BASKET > // found on file: dst00459.root > ////////////////////////////////////////////////////////// > > //Reset ROOT and connect tree file > gROOT->Reset(); > TFile hfile("dep.root"); > page = new TCanvas("page","Example",0,0,500,700); > page->SetFillColor(10); > page->Divide(1,1); > > TH1F *h44 = new TH1F("h44","Example",100,0,50); > TH1F *h14 = new TH1F("h14","Example",100,0,50); > // Of course there h4 is the same. > > // It's correct > // h44->Add(h4,h4); > // h14->Add(h44,h4,1,-1); > // There are nice figures > > // It's wrong > h44=(*h4)+(*h4); > h14=(*h4); > // There is nothing ... > > The statement h44 = (*h4) + (*h4) is wrong. h44 has been defined as a pointer to a TH1F. It must be an object, not a pointer. Do: TH1F result = (*h4) + (*h4) Rene Brun
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