QC-1290 Possibility to have evenly-spaced trends against run numbers

Framework/include/QualityControl/SliceTrendingTask.h

@@ -65,8 +65,12 @@ class SliceTrendingTask : public PostProcessingInterface
   void finalize(Trigger, framework::ServiceRegistryRef) final;
 
  private:
+  static constexpr size_t MaxRunNumberStringLength = 6;
   struct MetaData {
+    // we store run numbers both as an integer and as a string to allow users to select whether they need
+    // a trend in integer or label domain (the latter will contain evenly-spaced data points)
     Int_t runNumber = 0;
+    char runNumberStr[MaxRunNumberStringLength + 1] = { 0 }; // 6 characters + null terminator
   };
   struct TitleSettings {
     std::string observableX;

Framework/include/QualityControl/TrendingTask.h

@@ -56,11 +56,15 @@ class TrendingTask : public PostProcessingInterface
   void finalize(Trigger, framework::ServiceRegistryRef) override;
 
  private:
+  static constexpr size_t MaxRunNumberStringLength = 6;
   struct {
+    // we store run numbers both as an integer and as a string to allow users to select whether they need
+    // a trend in integer or label domain (the latter will contain evenly-spaced data points)
     Long64_t runNumber = 0;
+    char runNumberStr[MaxRunNumberStringLength + 1] = { 0 }; // 6 characters + null terminator
     static const char* getBranchLeafList()
     {
-      return "runNumber/L";
+      return "runNumber/L:runNumberStr/C";
     }
   } mMetaData;
 

Framework/src/SliceTrendingTask.cxx

@@ -145,6 +145,8 @@ void SliceTrendingTask::trendValues(const Trigger& t,
     mTime = t.activity.mValidity.getMax() / 1000;
   }
   mMetaData.runNumber = t.activity.mId;
+  std::snprintf(mMetaData.runNumberStr, MaxRunNumberStringLength + 1, "%d", t.activity.mId);
+
   for (auto& dataSource : mConfig.dataSources) {
     mNumberPads[dataSource.name] = 0;
     mSources[dataSource.name]->clear();

Framework/src/TrendingTask.cxx

@@ -184,8 +184,9 @@ bool TrendingTask::trendValues(const Trigger& t, repository::DatabaseInterface&
     mTime = t.activity.mValidity.getMax() / 1000;
   }
   mMetaData.runNumber = t.activity.mId;
-  bool wereAllSourcesInvoked = true;
+  std::snprintf(mMetaData.runNumberStr, MaxRunNumberStringLength + 1, "%d", t.activity.mId);
 
+  bool wereAllSourcesInvoked = true;
   for (auto& dataSource : mConfig.dataSources) {
     if (!reductor_helpers::updateReductor(mReductors[dataSource.name].get(), t, dataSource, qcdb, *this)) {
       wereAllSourcesInvoked = false;

Modules/Common/src/TH1SliceReductor.cxx

@@ -134,15 +134,15 @@ void TH1SliceReductor::GetTH1StatsY(TH1* hist, float stats[3],
 
   // Safety measures.
   if (lowerBin <= 0 || upperBin <= 0) {
-    ILOG(Error, Support) << "Error: Negative bin in TH1ReducterTPC::GetTH1StatsY" << ENDM;
+    ILOG(Error, Support) << "Error: Negative bin in TH1SliceReductor::GetTH1StatsY" << ENDM;
     exit(0);
   }
   if (upperBin < lowerBin) {
-    ILOG(Error, Support) << "Error: Upper bin smaller than lower bin in TH1ReducterTPC::GetTH1StatsY" << ENDM;
+    ILOG(Error, Support) << "Error: Upper bin smaller than lower bin in TH1SliceReductor::GetTH1StatsY" << ENDM;
     exit(0);
   }
   if (nTotalBins < iterateBins) {
-    ILOG(Error, Support) << "Error: Bin region bigger than total amount of bins TH1ReducterTPC::GetTH1StatsY" << ENDM;
+    ILOG(Error, Support) << "Error: Bin region bigger than total amount of bins TH1SliceReductor::GetTH1StatsY" << ENDM;
     exit(0);
   }
 

doc/PostProcessing.md

@@ -287,7 +287,7 @@ In such case, to reduce a Monitor Object or Quality Object, one has to inherit R
 
 All the values are stored in a **TTree**.
 Each data source forms a separate branch, with its leaves being the individual values.
-Additionally added columns include a `time` branch and a `metadata` branch (now consisting only of `runNumber`).
+Additionally added columns include a `time` branch and a `metadata` branch, consisting of `runNumber` (integer) and `runNumberStr` (string/label).
 
 The TTree is stored back to the **QC database** each time it is updated.
 In addition, the class exposes the [`TTree::Draw`](https://root.cern/doc/master/classTTree.html#a73450649dc6e54b5b94516c468523e45) interface, which allows to instantaneously generate **plots** with trends, correlations or histograms that are also sent to the QC database.