[Python][UHI] Fix entry count after slicing operations

Author: siliataider

bindings/pyroot/pythonizations/test/uhi_indexing.py

@@ -300,6 +300,7 @@ def test_statistics_slice(self, hist_setup):
         sliced_hist_full = hist_setup[...]
 
         assert hist_setup.GetEffectiveEntries() == sliced_hist_full.GetEffectiveEntries()
+        assert sliced_hist_full.GetEntries() == sliced_hist_full.GetEffectiveEntries()
         assert hist_setup.Integral() == sliced_hist_full.Integral()
 
         # Check if slicing over a range updates the statistics
@@ -310,6 +311,7 @@ def test_statistics_slice(self, hist_setup):
 
         assert hist_setup.Integral() == sliced_hist.Integral()
         assert hist_setup.GetEffectiveEntries() == sliced_hist.GetEffectiveEntries()
+        assert sliced_hist.GetEntries() == sliced_hist.GetEffectiveEntries()
         assert hist_setup.GetStdDev() == pytest.approx(sliced_hist.GetStdDev(), rel=10e-5)
         assert hist_setup.GetMean() == pytest.approx(sliced_hist.GetMean(), rel=10e-5)
 

hist/hist/inc/TH1.h

@@ -281,7 +281,6 @@ class TH1 : public TNamed, public TAttLine, public TAttFill, public TAttMarker {
 
       // Update the statistics
       ResetStats();
-      fEntries = std::accumulate(dataArray, dataArray + newSize, 0.0);
    }
 
    template <typename T>
@@ -359,7 +358,6 @@ class TH1 : public TNamed, public TAttLine, public TAttFill, public TAttMarker {
 
       // Update the statistics
       ResetStats();
-      fEntries += std::accumulate(values.begin(), values.end(), 0.0);
    }
 
    template <typename T>