[hist] Propagate disabled dimensions in RHistFillContext

This enables RHist with RCategoricalAxis for RHistConcurrentFiller.

Author: hahnjo

hist/histv7/inc/ROOT/RHistFillContext.hxx

@@ -36,7 +36,16 @@ private:
    RHistStats fStats;
 
    /// \sa RHistConcurrentFiller::CreateFillContent()
-   explicit RHistFillContext(RHist<BinContentType> &hist) : fHist(&hist), fStats(hist.GetNDimensions()) {}
+   explicit RHistFillContext(RHist<BinContentType> &hist) : fHist(&hist), fStats(hist.GetNDimensions())
+   {
+      // Propagate disabled dimensions to the local histogram statistics object.
+      const auto &histStats = hist.GetStats();
+      for (std::size_t i = 0; i < histStats.GetNDimensions(); i++) {
+         if (!histStats.IsEnabled(i)) {
+            fStats.DisableDimension(i);
+         }
+      }
+   }
    RHistFillContext(const RHistFillContext<BinContentType> &) = delete;
    RHistFillContext(RHistFillContext<BinContentType> &&) = default;
    RHistFillContext<BinContentType> &operator=(const RHistFillContext<BinContentType> &) = delete;

hist/histv7/test/hist_concurrent.cxx

@@ -2,7 +2,9 @@
 
 #include <memory>
 #include <stdexcept>
+#include <string>
 #include <utility>
+#include <vector>
 
 TEST(RHistConcurrentFiller, Constructor)
 {
@@ -141,6 +143,53 @@ TEST(RHistFillContext, StressFillWeight)
    EXPECT_FLOAT_EQ(hist->ComputeMean(), 0.5);
 }
 
+TEST(RHistFillContext, FillCategorical)
+{
+   const std::vector<std::string> categories = {"a", "b", "c"};
+   const RCategoricalAxis axis(categories);
+   const std::vector<RAxisVariant> axes = {axis};
+   auto hist = std::make_shared<RHist<int>>(axes);
+
+   {
+      RHistConcurrentFiller filler(hist);
+      auto context = filler.CreateFillContext();
+      context->Fill("b");
+      context->Fill(std::make_tuple("c"));
+   }
+
+   EXPECT_EQ(hist->GetBinContent(RBinIndex(1)), 1);
+   std::array<RBinIndex, 1> indices = {2};
+   EXPECT_EQ(hist->GetBinContent(indices), 1);
+
+   EXPECT_EQ(hist->GetNEntries(), 2);
+   EXPECT_FLOAT_EQ(hist->ComputeNEffectiveEntries(), 2);
+}
+
+TEST(RHistFillContext, FillCategoricalWeight)
+{
+   const std::vector<std::string> categories = {"a", "b", "c"};
+   const RCategoricalAxis axis(categories);
+   const std::vector<RAxisVariant> axes = {axis};
+   auto hist = std::make_shared<RHist<float>>(axes);
+
+   {
+      RHistConcurrentFiller filler(hist);
+      auto context = filler.CreateFillContext();
+      context->Fill("b", RWeight(0.8));
+      context->Fill(std::make_tuple("c"), RWeight(0.9));
+   }
+
+   EXPECT_FLOAT_EQ(hist->GetBinContent(RBinIndex(1)), 0.8);
+   std::array<RBinIndex, 1> indices = {2};
+   EXPECT_FLOAT_EQ(hist->GetBinContent(indices), 0.9);
+
+   EXPECT_EQ(hist->GetNEntries(), 2);
+   EXPECT_FLOAT_EQ(hist->GetStats().GetSumW(), 1.7);
+   EXPECT_FLOAT_EQ(hist->GetStats().GetSumW2(), 1.45);
+   // Cross-checked with TH1
+   EXPECT_FLOAT_EQ(hist->ComputeNEffectiveEntries(), 1.9931034);
+}
+
 TEST(RHistFillContext, Flush)
 {
    static constexpr std::size_t Bins = 20;