prevent adding histograms to directory to enable multiple instances of the same class

[u/mrichter/AliRoot.git] / PWG2 / FLOW / AliFlowCommon / AliFlowAnalysisWithFittingQDistribution.cxx

diff --git a/PWG2/FLOW/AliFlowCommon/AliFlowAnalysisWithFittingQDistribution.cxx b/PWG2/FLOW/AliFlowCommon/AliFlowAnalysisWithFittingQDistribution.cxx
index 7f59497bcf497234297c50c443e67df305c23ebb..08cf1839ac7341b50784a0332d64348b17660da2 100644 (file)
--- a/PWG2/FLOW/AliFlowCommon/AliFlowAnalysisWithFittingQDistribution.cxx
+++ b/PWG2/FLOW/AliFlowCommon/AliFlowAnalysisWithFittingQDistribution.cxx
@@ -132,6 +132,12 @@ void AliFlowAnalysisWithFittingQDistribution::Init()
 {
  // access constants and book everything
  
+ //save old value and prevent histograms from being added to directory
+ //to avoid name clashes in case multiple analaysis objects are used
+ //in an analysis
+ Bool_t oldHistAddStatus = TH1::AddDirectoryStatus();
+ TH1::AddDirectory(kFALSE);
+ 
  // access constants:
  this->AccessConstants();
  
@@ -151,6 +157,8 @@ void AliFlowAnalysisWithFittingQDistribution::Init()
  // set harmonic in common control histograms (to be improved (should I do this somewhere else?)):
  (fCommonHists->GetHarmonic())->Fill(0.5,fHarmonic); 
  
+ //restore old status
+ TH1::AddDirectory(oldHistAddStatus);
 } // end of void AliFlowAnalysisWithFittingQDistribution::Init()