Add getBin() calls and example of counters to the mixing event tutorial. (#6092)

Author: saganatt

Tutorials/src/eventMixing.cxx

@@ -49,7 +49,11 @@ struct MixedEvents {
 
     int count = 0;
     for (auto& [c1, tracks1, c2, tracks2] : pair) {
-      LOGF(info, "Mixed event collisions: (%d, %d)", c1.globalIndex(), c2.globalIndex());
+      // Example of using getBin() to check collisions bin
+      // NOTE that it is a bit different for FlexibleBinning -- check in respective example
+      int bin = binningOnPositions.getBin({c1.posX(), c1.posY()});
+
+      LOGF(info, "Mixed event collisions: (%d, %d) from bin %d", c1.globalIndex(), c2.globalIndex(), bin);
       count++;
       if (count == 100)
         break;
@@ -434,7 +438,10 @@ struct MixedEventsLambdaBinning {
 
     int count = 0;
     for (auto& [c1, tracks1, c2, tracks2] : pair) {
-      LOGF(info, "Mixed event collisions: (%d, %d) z: (%.3f, %.3f), tracks size (%d, %d)", c1.globalIndex(), c2.globalIndex(), c1.posZ(), c2.posZ(), tracks1.size(), tracks2.size());
+      // NOTE that getBin() with FlexibleBinningPolicy needs explicit tuple construction
+      int bin = binningWithLambda.getBin(std::tuple(getTracksSize(c1), c1.posZ()));
+
+      LOGF(info, "Mixed event collisions: (%d, %d) from bin %d z: (%.3f, %.3f), tracks size (%d, %d)", c1.globalIndex(), c2.globalIndex(), bin, c1.posZ(), c2.posZ(), tracks1.size(), tracks2.size());
       count++;
       if (count == 100)
         break;
@@ -451,6 +458,30 @@ struct MixedEventsLambdaBinning {
   }
 };
 
+struct MixedEventsCounters {
+  // Please read carefully the tutorial description in O2 documentation to understand the behaviour of currentWindowNeighbours().
+  // https://aliceo2group.github.io/analysis-framework/docs/tutorials/eventMixing.html#mixedeventscounters
+
+  SliceCache cache;
+
+  std::vector<double> xBins{VARIABLE_WIDTH, -0.064, -0.062, -0.060, 0.066, 0.068, 0.070, 0.072};
+  std::vector<double> yBins{VARIABLE_WIDTH, -0.320, -0.301, -0.300, 0.330, 0.340, 0.350, 0.360};
+  using BinningType = ColumnBinningPolicy<aod::collision::PosX, aod::collision::PosY>;
+  BinningType binningOnPositions{{xBins, yBins}, true};
+  // true is for 'ignore overflows' (true by default)
+  SameKindPair<aod::Collisions, aod::Tracks, BinningType> pair{binningOnPositions, 5, -1, &cache}; // indicates that 5 events should be mixed and under / overflow(-1) to be ignored
+
+  void process(aod::Collisions const& collisions, aod::Tracks const& tracks)
+  {
+    LOGF(info, "Input data Collisions %d, Tracks %d ", collisions.size(), tracks.size());
+
+    for (auto it = pair.begin(); it != pair.end(); it++) {
+      auto& [c1, tracks1, c2, tracks2] = *it;
+      LOGF(info, "Mixed event collisions: (%d, %d), is it first pair with %d: %d, number of collisions mixed with the first: %d", c1.globalIndex(), c2.globalIndex(), c1.globalIndex(), it.isNewWindow(), it.currentWindowNeighbours());
+    }
+  }
+};
+
 WorkflowSpec defineDataProcessing(ConfigContext const& cfgc)
 {
   return WorkflowSpec{
@@ -466,5 +497,6 @@ WorkflowSpec defineDataProcessing(ConfigContext const& cfgc)
     adaptAnalysisTask<MixedEventsWithHashTask>(cfgc),
     adaptAnalysisTask<MixedEventsPartitionedTracks>(cfgc),
     adaptAnalysisTask<MixedEventsLambdaBinning>(cfgc),
+    adaptAnalysisTask<MixedEventsCounters>(cfgc),
   };
 }

Tutorials/src/eventMixingValidation.cxx

@@ -121,39 +121,11 @@ struct MixedEventsJoinedTracks {
 //  }
 //};
 
-struct MixedEventsCounters {
-  SliceCache cache;
-  // This task shows how to extract variables needed for weighted correlations.
-  // NOTE: The same number of currentWindowNeighbours is returned for all kinds of block combinations.
-  // Strictly upper: the first collision will is paired with exactly currentWindowNeighbours other collisions.
-  // Upper: the first collision is paired with (currentWindowNeighbours + 1) collisions, including itself.
-  // Full: (currentWindowNeighbours + 1) pairs with the first collision in the first position (c1)
-  //       + there are other combinations with the first collision at other positions.
-
-  std::vector<double> xBins{VARIABLE_WIDTH, -0.064, -0.062, -0.060, 0.066, 0.068, 0.070, 0.072};
-  std::vector<double> yBins{VARIABLE_WIDTH, -0.320, -0.301, -0.300, 0.330, 0.340, 0.350, 0.360};
-  using BinningType = ColumnBinningPolicy<aod::collision::PosX, aod::collision::PosY>;
-  BinningType binningOnPositions{{xBins, yBins}, true};
-  // true is for 'ignore overflows' (true by default)
-  SameKindPair<aod::Collisions, aod::Tracks, BinningType> pair{binningOnPositions, 5, -1, &cache}; // indicates that 5 events should be mixed and under / overflow(-1) to be ignored
-
-  void process(aod::Collisions const& collisions, aod::Tracks const& tracks)
-  {
-    LOGF(info, "Input data Collisions %d, Tracks %d ", collisions.size(), tracks.size());
-
-    for (auto it = pair.begin(); it != pair.end(); it++) {
-      auto& [c1, tracks1, c2, tracks2] = *it;
-      LOGF(info, "Mixed event collisions: (%d, %d), is it first pair with %d: %d, number of collisions mixed with the first: %d", c1.globalIndex(), c2.globalIndex(), c1.globalIndex(), it.isNewWindow(), it.currentWindowNeighbours());
-    }
-  }
-};
-
 WorkflowSpec defineDataProcessing(ConfigContext const& cfgc)
 {
   return WorkflowSpec{
     adaptAnalysisTask<MixedEventsEmptyTables>(cfgc),
     adaptAnalysisTask<MixedEventsJoinedTracks>(cfgc),
     // adaptAnalysisTask<MixedEventsBadSubscription>(cfgc), // Should not compile
-    adaptAnalysisTask<MixedEventsCounters>(cfgc),
   };
 }