[hist] Enable chi2 tests for TProfile

hist/hist/inc/TProfile.h

@@ -89,7 +89,8 @@ class TProfile : public TH1D {
    Bool_t   Add(const TH1 *h1, const TH1 *h2, Double_t c1=1, Double_t c2=1) override; // *MENU*
    static  void     Approximate(Bool_t approx=kTRUE);
    Int_t    BufferEmpty(Int_t action=0) override;
-           void     BuildOptions(Double_t ymin, Double_t ymax, Option_t *option);
+   void     BuildOptions(Double_t ymin, Double_t ymax, Option_t *option);
+   Double_t Chi2Test(const TH1* h2, Option_t *option = "WW", Double_t *res = nullptr) const override;
    void     Copy(TObject &hnew) const override;
    Bool_t   Divide(TF1 *h1, Double_t c1=1) override;
    Bool_t   Divide(const TH1 *h1) override;

hist/hist/inc/TProfile2D.h

@@ -95,6 +95,7 @@ class TProfile2D : public TH2D {
    static  void      Approximate(Bool_t approx=kTRUE);
    void              BuildOptions(Double_t zmin, Double_t zmax, Option_t *option);
    Int_t     BufferEmpty(Int_t action=0) override;
+   Double_t  Chi2Test(const TH1* h2, Option_t *option = "WW", Double_t *res = nullptr) const override;
    void      Copy(TObject &hnew) const override;
    Bool_t    Divide(TF1 *h1, Double_t c1=1) override;
    Bool_t    Divide(const TH1 *h1) override;

hist/hist/inc/TProfile3D.h

@@ -100,6 +100,7 @@ class TProfile3D : public TH3D {
    static  void      Approximate(Bool_t approx=kTRUE);
    void              BuildOptions(Double_t tmin, Double_t tmax, Option_t *option);
    Int_t     BufferEmpty(Int_t action=0) override;
+   Double_t  Chi2Test(const TH1* h2, Option_t *option = "WW", Double_t *res = nullptr) const override;
    void      Copy(TObject &hnew) const override;
    Bool_t    Divide(TF1 *h1, Double_t c1=1) override;
    Bool_t    Divide(const TH1 *h1) override;

hist/hist/src/TProfile.cxx

@@ -416,6 +416,34 @@ Int_t TProfile::BufferFill(Double_t x, Double_t y, Double_t w)
    return -2;
 }
 
+////////////////////////////////////////////////////////////////////////////////
+/// Run a Chi2Test between a TProfileD and another histogram.
+/// If the argument is also a TProfileD, this calls TH1::Chi2Test() with the option "WW".
+/// \see TH1::Chi2Test()
+
+Double_t TProfile::Chi2Test(const TH1 *h2, Option_t *option, Double_t *res) const
+{
+   TString opt = option;
+   opt.ToUpper();
+
+   if (auto other = dynamic_cast<const TProfile *>(h2); other) {
+      if (fErrorMode != kERRORMEAN || other->fErrorMode != kERRORMEAN) {
+         Error("Chi2Test", "Chi2 tests need TProfiles in 'error of mean' mode.");
+         return 0;
+      }
+
+      opt += "WW";
+      opt.ReplaceAll("UU", "WW");
+      opt.ReplaceAll("UW", "WW");
+   } else if (!opt.Contains("WW")) {
+      Error("Chi2Test", "TProfiles need to be tested with the 'W' option. Either use option 'WW' or use "
+                        "histogram.Chi2Test(<profile>, 'UW')");
+      return 0;
+   }
+
+   return TH1::Chi2Test(h2, opt, res);
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 /// Copy a Profile histogram to a new profile histogram.
 

hist/hist/src/TProfile2D.cxx

@@ -379,6 +379,34 @@ Int_t TProfile2D::BufferFill(Double_t x, Double_t y, Double_t z, Double_t w)
    return -2;
 }
 
+////////////////////////////////////////////////////////////////////////////////
+/// Run a Chi2Test between a TProfile2D and another histogram.
+/// If the argument is also a TProfile2D, this calls TH1::Chi2Test() with the option "WW".
+/// \see TH1::Chi2Test()
+
+Double_t TProfile2D::Chi2Test(const TH1 *h2, Option_t *option, Double_t *res) const
+{
+   TString opt = option;
+   opt.ToUpper();
+
+   if (auto other = dynamic_cast<const TProfile2D *>(h2); other) {
+      if (fErrorMode != kERRORMEAN || other->fErrorMode != kERRORMEAN) {
+         Error("Chi2Test", "Chi2 tests need TProfiles in 'error of mean' mode.");
+         return 0;
+      }
+
+      opt += "WW";
+      opt.ReplaceAll("UU", "WW");
+      opt.ReplaceAll("UW", "WW");
+   } else if (!opt.Contains("WW")) {
+      Error("Chi2Test", "TProfiles need to be tested with the 'W' option. Either use option 'WW' or use "
+                        "histogram.Chi2Test(<profile>, 'UW')");
+      return 0;
+   }
+
+   return TH1::Chi2Test(h2, opt, res);
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 /// Copy a Profile2D histogram to a new profile2D histogram.
 

hist/hist/src/TProfile3D.cxx

@@ -343,6 +343,34 @@ Int_t TProfile3D::BufferFill(Double_t x, Double_t y, Double_t z, Double_t t, Dou
    return -2;
 }
 
+////////////////////////////////////////////////////////////////////////////////
+/// Run a Chi2Test between a TProfile3D and another histogram.
+/// If the argument is also a TProfile3D, this calls TH1::Chi2Test() with the option "WW".
+/// \see TH1::Chi2Test()
+
+Double_t TProfile3D::Chi2Test(const TH1 *h2, Option_t *option, Double_t *res) const
+{
+   TString opt = option;
+   opt.ToUpper();
+
+   if (auto other = dynamic_cast<const TProfile3D *>(h2); other) {
+      if (fErrorMode != kERRORMEAN || other->fErrorMode != kERRORMEAN) {
+         Error("Chi2Test", "Chi2 tests need TProfiles in 'error of mean' mode.");
+         return 0;
+      }
+
+      opt += "WW";
+      opt.ReplaceAll("UU", "WW");
+      opt.ReplaceAll("UW", "WW");
+   } else if (!opt.Contains("WW")) {
+      Error("Chi2Test", "TProfiles need to be tested with the 'W' option. Either use option 'WW' or use "
+                        "histogram.Chi2Test(<profile>, 'UW')");
+      return 0;
+   }
+
+   return TH1::Chi2Test(h2, opt, res);
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 /// Copy a Profile3D histogram to a new profile2D histogram.
 

hist/hist/test/CMakeLists.txt

@@ -29,6 +29,7 @@ ROOT_ADD_GTEST(testTGraphSorting test_TGraph_sorting.cxx LIBRARIES Hist)
 ROOT_ADD_GTEST(testSpline test_spline.cxx LIBRARIES Hist)
 ROOT_ADD_GTEST(testTF1Simple test_tf1_simple.cxx LIBRARIES Hist RIO)
 ROOT_ADD_GTEST(testTF1DrawCopy test_tf1_drawcopy.cxx LIBRARIES Hist)
+ROOT_ADD_GTEST(test_TProfile test_TProfile.cxx LIBRARIES Hist)
 
 if(fftw3)
   ROOT_ADD_GTEST(testTF1 test_tf1.cxx LIBRARIES Hist)

hist/hist/test/test_TProfile.cxx

@@ -0,0 +1,93 @@
+#include "gtest/gtest.h"
+
+#include "TProfile.h"
+#include "TProfile2D.h"
+#include "TProfile3D.h"
+#include "TRandom.h"
+
+#include "ROOT/TestSupport.hxx"
+
+template <typename T>
+void runTest(T const &reference, T const &sameDistr, T const &differentDistr)
+{
+   EXPECT_EQ(reference.Chi2Test(&sameDistr), reference.Chi2Test(&sameDistr, "WW"));
+   EXPECT_EQ(reference.Chi2Test(&sameDistr),
+             reference.Chi2Test(&sameDistr, "P WW UW")); // Need more than just the default option
+   EXPECT_EQ(reference.Chi2Test(&sameDistr), reference.Chi2Test(&sameDistr, "UW"));
+   EXPECT_EQ(reference.Chi2Test(&sameDistr), reference.Chi2Test(&sameDistr, "UU"));
+   EXPECT_EQ(reference.Chi2Test(&sameDistr), reference.Chi2Test(&sameDistr, "P UU"));
+
+   const double probSuccess = reference.Chi2Test(&sameDistr, "P");
+   EXPECT_GT(probSuccess, 0.1);
+   EXPECT_LE(probSuccess, 1.);
+   const double probFail = reference.Chi2Test(&differentDistr, "P");
+   EXPECT_LT(probFail, 0.05);
+}
+
+TEST(TProfile, Chi2Test)
+{
+   TProfile reference("reference", "reference", 10, 0, 10);
+   TProfile sameDistr("sameDistr", "sameDistr", 10, 0, 10);
+   TProfile differentDistr("differentDistr", "differentDistr", 10, 0, 10);
+
+   gRandom->SetSeed(1);
+   for (unsigned int i = 0; i < 100000; i++) {
+      const double x = gRandom->Uniform(10.);
+      reference.Fill(x, gRandom->Gaus(5 + x / 2, 5.));
+      sameDistr.Fill(x, gRandom->Gaus(5 + x / 2, 5.));
+      differentDistr.Fill(x, gRandom->Gaus(20, 1.));
+   }
+
+   runTest(reference, sameDistr, differentDistr);
+}
+
+TEST(TProfile, Chi2TestWithWrongErrors)
+{
+   TProfile reference("reference", "reference", 10, 0, 10);
+   reference.Fill(1, 2);
+   reference.Fill(1, 3);
+
+   for (auto err : {"s", "i", "g"}) {
+      ROOT::TestSupport::CheckDiagsRAII checkDiag(kError, "TProfile::Chi2Test", "error of mean", false);
+
+      TProfile sameDistr("sameDistr", "sameDistr", 10, 0, 10, err);
+      sameDistr.Fill(1, 2);
+      sameDistr.Fill(1, 3);
+
+      reference.Chi2Test(&sameDistr);
+   }
+}
+
+TEST(TProfile2D, Chi2Test)
+{
+   TProfile2D reference("reference", "reference", 10, 0, 10, 10, 0, 10);
+   TProfile2D sameDistr("sameDistr", "sameDistr", 10, 0, 10, 10, 0, 10);
+   TProfile2D differentDistr("differentDistr", "differentDistr", 10, 0, 10, 10, 0, 10);
+
+   gRandom->SetSeed(1);
+   for (unsigned int i = 0; i < 50000; i++) {
+      const double x = gRandom->Uniform(10.);
+      reference.Fill(x, x + 1., gRandom->Gaus(5 + x / 2, 5.));
+      sameDistr.Fill(x, x + 1., gRandom->Gaus(5 + x / 2, 5.));
+      differentDistr.Fill(x, x + 1., gRandom->Gaus(20, 1.));
+   }
+
+   runTest(reference, sameDistr, differentDistr);
+}
+
+TEST(TProfile3D, Chi2Test)
+{
+   TProfile3D reference("reference", "reference", 10, 0, 10, 11, 0, 11, 12, 0, 12);
+   TProfile3D sameDistr("sameDistr", "sameDistr", 10, 0, 10, 11, 0, 11, 12, 0, 12);
+   TProfile3D differentDistr("differentDistr", "differentDistr", 10, 0, 10, 11, 0, 11, 12, 0, 12);
+
+   gRandom->SetSeed(1);
+   for (unsigned int i = 0; i < 50000; i++) {
+      const double x = gRandom->Uniform(10.);
+      reference.Fill(x, x + 1., x + 2., gRandom->Gaus(5 + x / 2, 5.));
+      sameDistr.Fill(x, x + 1., x + 2., gRandom->Gaus(5 + x / 2, 5.));
+      differentDistr.Fill(x, x + 1., x + 2., gRandom->Gaus(20, 1.));
+   }
+
+   runTest(reference, sameDistr, differentDistr);
+}