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root:thstack [2012/08/16 11:58] (current) – created nchiap
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 +====== Using and Troubleshooting THStack ======
 +
 +===== Basic Code =====
 +<code c++>
 +  TH1F *h;
 +  THStack *hs = new THStack("hs","Stacked 1D histograms");
 +  //create three 1-d histograms
 +  for (int i = 0; i < 3; i++) {
 +    h = new TH1F("h"+i,"test hstack",100,-4,4);
 +    h->FillRandom("gaus",20000-i*5000);
 +    h->SetFillColor(i+2);
 +    h->SetMarkerColor(i+2);
 +    hs->Add(h);
 +  }
 +  TCanvas *cst = new TCanvas("cst","stacked hists",10,10,700,700);
 +  cst->SetFillColor(41);
 +  hs->Draw()
 +</code>
 +
 +===== Troubleshooting =====
 +==== Y Axis Range ====
 +see [[root:setaxisrange#y_axis_of_a_thstack | Set Display Range of Axis]]
 +
 +==== Scaling/Normalising Histograms ====
 +**Do not use** ''SetNormFactor(normFactor)''
 +
 +If ''SetNormFactor'' on a histogram has been called, this histogram will not be stacked, but is painted seperately (as with ''nostack'').
 +Instead use the following code to normalise histogram ''h''
 +<code c++>
 +h->Scale(normFactor/h->Integral());
 +</code>
 +
 +
 +
  
root/thstack.txt · Last modified: 2012/08/16 11:58 by nchiap