[math][fitter] Fix crash when doing a weighted likelihood fit

lmoneta · lmoneta · commit c911204903d9 · 2024-01-26T17:49:54.000+01:00
A bug was introduced in #10439 affecting the weighted likelihood fits Add missing test for Weighted likelihood fits in stressHistoFit
diff --git a/math/mathcore/src/Fitter.cxx b/math/mathcore/src/Fitter.cxx
@@ -847,14 +847,16 @@ bool Fitter::DoMinimization(std::unique_ptr<ObjFunc_t>  objFunc, const ROOT::Mat
 template<class ObjFunc_t>
 bool Fitter::DoWeightMinimization(std::unique_ptr<ObjFunc_t> objFunc, const ROOT::Math::IMultiGenFunction * chi2func) {
    // perform the minimization initializing the minimizer starting from a given obj function
-   // and apply afterwards the correction for weights. This applyies only for logL fitting
+   // and apply afterwards the correction for weights. This applies only for logL fitting
    this->fFitType = objFunc->Type();
    fExtObjFunction = nullptr;
-   fObjFunction = std::move(objFunc);
+   // need to use a temporary shared pointer to the objective function since we cannot use the unique pointer when it has been moved
+   std::shared_ptr<ObjFunc_t> sObjFunc{ std::move(objFunc)};
+   fObjFunction = sObjFunc;
    if (!DoInitMinimizer()) return false;
    if (!DoMinimization(chi2func)) return false;
-   objFunc->UseSumOfWeightSquare();
-   return ApplyWeightCorrection(*objFunc);
+   sObjFunc->UseSumOfWeightSquare();
+   return ApplyWeightCorrection(*sObjFunc);
 }
 
 
diff --git a/test/stressHistoFit.cxx b/test/stressHistoFit.cxx
@@ -771,6 +771,7 @@ int test1DObjects(vector< vector<algoType> >& listH,
       for (int i = 1; i <= h1->GetNbinsX() + 1; ++i)
          h1->SetBinContent(i, rndm.Poisson(func->Eval(h1->GetBinCenter(i))));
 
+      h1->Sumw2(); // make as a weighted histo to test weighted fits
       gTestIndex++;
       if (gSelectedTest == 0 || gSelectedTest == gTestIndex) {
          // fill equal bin 1D  histogram
@@ -803,7 +804,7 @@ int test1DObjects(vector< vector<algoType> >& listH,
                                              h2->GetXaxis()->GetBinUpEdge(i));
             h2->SetBinContent(i,rndm.Poisson(expValue));
          }
-
+         h2->Sumw2(); // make as a weighted histo to test weighted fits
          if (c0 && !__DRAW__) delete c0;
          c0 = new TCanvas(TString::Format("c%d_H1D", gTestIndex), "Histogram1D Variable");
          ObjectWrapper<TH1D *> owh2(h2);
@@ -1219,6 +1220,7 @@ void init_structures()
    noGraphAlgos.push_back( algoType( "Minuit2",     "Migrad",      "EX", CompareResult()) );
    noGraphAlgos.push_back( algoType( "Minuit",      "Migrad",      "L", CompareResult(defCmpOpt,3,0.1)) );  // normal binned likelihood fit
    noGraphAlgos.push_back( algoType( "Minuit2",     "Migrad",      "L", CompareResult(defCmpOpt,3,0.1)) );
+   noGraphAlgos.push_back( algoType( "Minuit2",     "Migrad",      "WL", CompareResult(defCmpOpt,3,0.1)) );
    noGraphAlgos.push_back( algoType( "Minuit2",     "Migrad",      "G", CompareResult()) ); // gradient chi2 fit
    //noGraphAlgos.push_back( algoType( "Minuit",      "Migrad",      "G", CompareResult()) );   // skip TMinuit with G
    noGraphAlgos.push_back( algoType( "Minuit2",     "Minimize",    "G", CompareResult()) );
