add protection for empty input histogram in the fitting function

cms-sw · Aug 24, 2022 · e03333c · e03333c
1 parent c5d5f23
commit e03333c
Show file tree

Hide file tree

Showing 2 changed files with 15 additions and 4 deletions.
diff --git a/DQMOffline/Alignment/interface/DiMuonMassBiasClient.h b/DQMOffline/Alignment/interface/DiMuonMassBiasClient.h
@@ -48,6 +48,9 @@ namespace diMuonMassBias {
     assert(v.size() == 3);
     std::copy(std::begin(v), std::end(v), x);
   }
+
+  static constexpr int minimumHits = 10;
+
 }  // namespace diMuonMassBias
 
 class DiMuonMassBiasClient : public DQMEDHarvester {
@@ -83,7 +86,7 @@ class DiMuonMassBiasClient : public DQMEDHarvester {
 
   float meanConfig_[3];  /* parmaeters for the fit: mean */
   float widthConfig_[3]; /* parameters for the fit: width */
-  float sigmaConfig_[3]; /* parmaeters for the fit: sigma */
+  float sigmaConfig_[3]; /* parameters for the fit: sigma */
 
   // list of histograms to harvest
   std::vector<std::string> MEtoHarvest_;

diff --git a/DQMOffline/Alignment/src/DiMuonMassBiasClient.cc b/DQMOffline/Alignment/src/DiMuonMassBiasClient.cc
@@ -146,6 +146,14 @@ void DiMuonMassBiasClient::dqmEndJob(DQMStore::IBooker& ibooker, DQMStore::IGett
 diMuonMassBias::fitOutputs DiMuonMassBiasClient::fitVoigt(TH1* hist, const bool& fitBackground) const
 //-----------------------------------------------------------------------------------
 {
+  if (hist->GetEntries() < diMuonMassBias::minimumHits) {
+    edm::LogWarning("DiMuonMassBiasClient") << " Input histogram:" << hist->GetName() << " has not enough entries ("
+                                            << hist->GetEntries() << ") for a meaningful Voigtian fit!\n"
+                                            << "Skipping!";
+
+    return diMuonMassBias::fitOutputs(Measurement1D(0., 0.), Measurement1D(0., 0.));
+  }
+
   TCanvas* c1 = new TCanvas();
   if (debugMode_) {
     c1->Clear();
@@ -168,9 +176,9 @@ diMuonMassBias::fitOutputs DiMuonMassBiasClient::fitVoigt(TH1* hist, const bool&
   RooDataHist datahist("datahist", "datahist", InvMass, RooFit::Import(*hist));
   datahist.plotOn(frame);
 
-  RooRealVar mean("#mu", "mean", meanConfig_[0], meanConfig_[1], meanConfig_[2]);          //90.0, 60.0, 120.0
-  RooRealVar width("width", "width", widthConfig_[0], widthConfig_[1], widthConfig_[2]);   // 5.0,  0.0, 120.0
-  RooRealVar sigma("#sigma", "sigma", sigmaConfig_[0], sigmaConfig_[1], sigmaConfig_[2]);  // 5.0,  0.0, 120.0
+  RooRealVar mean("#mu", "mean", meanConfig_[0], meanConfig_[1], meanConfig_[2]);          //90.0, 60.0, 120.0 (for Z)
+  RooRealVar width("width", "width", widthConfig_[0], widthConfig_[1], widthConfig_[2]);   // 5.0,  0.0, 120.0 (for Z)
+  RooRealVar sigma("#sigma", "sigma", sigmaConfig_[0], sigmaConfig_[1], sigmaConfig_[2]);  // 5.0,  0.0, 120.0 (for Z)
   RooVoigtian voigt("voigt", "voigt", InvMass, mean, width, sigma);
 
   RooRealVar lambda("#lambda", "slope", -0.01, -100., 1.);