Add a generic reference data comparator

The code introduces some tools that allow to compare the plots produced by given task(s) with that of a reference run:
- `ReferenceComparatorTask` draws histograms with their reference superimposed, as well as the ratio between histograms and reference
- `ReferenceComparatorCheck` compares the histograms with their corresponding reference, and assesses their compatibility. The comparison is performed by a dynamically loadable module that provides the actual comparison algorithm
- `ReferenceComparatorPlot` is an utility class to draw the current and reference histograms, and their ratio
- `ObjectComparator*` are dynamically loadable modules than implement different histogram comparison methods
  Three examples are provided:
    - `ObjectComparatorDeviation` evaluates the average relative difference between the histogram bins
    - `ObjectComparatorChi2` compares the histograms using a chi2-based test
    - `ObjectComparatorKolmogorov` compares the histograms using a Kolmogorov test

Modules/Common/CMakeLists.txt

@@ -22,6 +22,13 @@ target_sources(O2QcCommon
                        src/CcdbInspectorTask.cxx
                        src/CcdbInspectorTaskConfig.cxx
                        src/CcdbInspectorCheck.cxx
+                       src/ObjectComparatorDeviation.cxx
+                       src/ObjectComparatorChi2.cxx
+                       src/ObjectComparatorKolmogorov.cxx
+                       src/ReferenceComparatorPlot.cxx
+                       src/ReferenceComparatorTask.cxx
+                       src/ReferenceComparatorTaskConfig.cxx
+                       src/ReferenceComparatorCheck.cxx
                        src/NonEmpty.cxx
                        src/MeanIsAbove.cxx
                        src/TH1Reductor.cxx
@@ -54,6 +61,12 @@ add_root_dictionary(O2QcCommon
                             include/Common/BigScreen.h
                             include/Common/CcdbInspectorTask.h
                             include/Common/CcdbInspectorCheck.h
+                            include/Common/ObjectComparatorInterface.h
+                            include/Common/ObjectComparatorDeviation.h
+                            include/Common/ObjectComparatorChi2.h
+                            include/Common/ObjectComparatorKolmogorov.h
+                            include/Common/ReferenceComparatorTask.h
+                            include/Common/ReferenceComparatorCheck.h
                             include/Common/MeanIsAbove.h
                             include/Common/TH1Ratio.h
                             include/Common/TH2Ratio.h

Modules/Common/etc/reference-comparator-example.json

@@ -0,0 +1,98 @@
+{
+  "qc": {
+    "config": {
+      "database": {
+        "implementation": "CCDB",
+        "host": "ccdb-test.cern.ch:8080",
+        "username": "not_applicable",
+        "password": "not_applicable",
+        "name": "not_applicable"
+      },
+      "Activity": {
+      },
+      "monitoring": {
+        "url": "infologger:///debug?qc"
+      },
+      "consul": {
+        "url": ""
+      },
+      "conditionDB": {
+        "url": "ccdb-test.cern.ch:8080"
+      }
+    },
+    "postprocessing": {
+      "ExampleRefComp": {
+        "active": "true",
+        "className": "o2::quality_control_modules::common::ReferenceComparatorTask",
+        "moduleName": "QualityControl",
+        "detectorName": "MCH",
+        "extendedTaskParameters": {
+          "default": {
+            "default": {
+              "notOlderThan" : "300",
+              "referenceRun" : "551875"
+            }
+          },
+          "PHYSICS": {
+            "PROTON-PROTON": {
+              "referenceRun" : "551890"
+            }
+          }
+        },
+        "dataGroups": [
+          {
+            "name": "Tracks",
+            "inputPath": "MCH/MO/Tracks/WithCuts",
+            "referencePath": "MCH/MO/Tracks",
+            "outputPath": "Tracks/WithCuts",
+            "normalizeReference": "true",
+            "drawRatioOnly": "false",
+            "drawOption1D": "E",
+            "drawOption2D": "COL",
+            "inputObjects": [
+              "TrackEta",
+              "TrackEtaPhi"
+            ]
+          }
+        ],
+        "initTrigger": [
+          "userorcontrol"
+        ],
+        "updateTrigger": [
+          "60 seconds"
+        ],
+        "stopTrigger": [
+          "userorcontrol"
+        ]
+      }
+    },
+    "checks": {
+      "ExampleRefCheck": {
+        "active": "true",
+        "className": "o2::quality_control_modules::common::ReferenceComparatorCheck",
+        "moduleName": "QualityControl",
+        "detectorName": "MCH",
+        "policy": "OnAny",
+        "extendedCheckParameters": {
+          "default": {      
+            "default": {      
+              "moduleName" : "QualityControl",
+              "comparatorName" : "o2::quality_control_modules::common::ObjectComparatorChi2",
+              "threshold" : "0.5"
+            }
+          }
+        },
+        "dataSource": [
+          {
+            "type": "PostProcessing",
+            "name": "ExampleRefComp",
+             "MOs" : [
+               "Tracks/WithCuts/TrackEta",
+               "Tracks/WithCuts/TrackEtaPhi"
+            ]
+          }
+        ]
+      }
+    }
+  }
+}

Modules/Common/include/Common/LinkDef.h

@@ -19,6 +19,11 @@
 #pragma link C++ class o2::quality_control_modules::common::BigScreen + ;
 #pragma link C++ class o2::quality_control_modules::common::CcdbInspectorTask + ;
 #pragma link C++ class o2::quality_control_modules::common::CcdbInspectorCheck + ;
+#pragma link C++ class o2::quality_control_modules::common::ObjectComparatorDeviation + ;
+#pragma link C++ class o2::quality_control_modules::common::ObjectComparatorChi2 + ;
+#pragma link C++ class o2::quality_control_modules::common::ObjectComparatorKolmogorov + ;
+#pragma link C++ class o2::quality_control_modules::common::ReferenceComparatorTask + ;
+#pragma link C++ class o2::quality_control_modules::common::ReferenceComparatorCheck + ;
 #pragma link C++ class o2::quality_control_modules::common::WorstOfAllAggregator + ;
 #pragma link C++ class o2::quality_control_modules::common::IncreasingEntries + ;
 #pragma link C++ class o2::quality_control_modules::common::TH1SliceReductor + ;

Modules/Common/include/Common/ObjectComparatorChi2.h

@@ -0,0 +1,42 @@
+// Copyright 2019-2020 CERN and copyright holders of ALICE O2.
+// See https://alice-o2.web.cern.ch/copyright for details of the copyright holders.
+// All rights not expressly granted are reserved.
+//
+// This software is distributed under the terms of the GNU General Public
+// License v3 (GPL Version 3), copied verbatim in the file "COPYING".
+//
+// In applying this license CERN does not waive the privileges and immunities
+// granted to it by virtue of its status as an Intergovernmental Organization
+// or submit itself to any jurisdiction.
+
+///
+/// \file   ObjectComparatorChi2.h
+/// \author Andrea Ferrero
+/// \brief  A class for comparing two histogram objects based on a chi2 test
+///
+
+#ifndef QUALITYCONTROL_ObjectComparatorChi2_H
+#define QUALITYCONTROL_ObjectComparatorChi2_H
+
+#include "Common/ObjectComparatorInterface.h"
+
+namespace o2::quality_control_modules::common
+{
+
+/// \brief A class for comparing two histogram objects based on a chi2 test
+class ObjectComparatorChi2 : public ObjectComparatorInterface
+{
+ public:
+  /// \brief Constructor
+  ObjectComparatorChi2() = default;
+  /// \brief Destructor
+  virtual ~ObjectComparatorChi2() = default;
+
+  /// \brief objects comparison function
+  /// \return the quality resulting from the object comparison
+  o2::quality_control::core::Quality compare(TObject* obj, TObject* objRef, std::string& message) override;
+};
+
+} // namespace o2::quality_control_modules::common
+
+#endif // QUALITYCONTROL_ObjectComparatorChi2_H

Modules/Common/include/Common/ObjectComparatorDeviation.h

@@ -0,0 +1,42 @@
+// Copyright 2019-2020 CERN and copyright holders of ALICE O2.
+// See https://alice-o2.web.cern.ch/copyright for details of the copyright holders.
+// All rights not expressly granted are reserved.
+//
+// This software is distributed under the terms of the GNU General Public
+// License v3 (GPL Version 3), copied verbatim in the file "COPYING".
+//
+// In applying this license CERN does not waive the privileges and immunities
+// granted to it by virtue of its status as an Intergovernmental Organization
+// or submit itself to any jurisdiction.
+
+///
+/// \file   ObjectComparatorDeviation.h
+/// \author Andrea Ferrero
+/// \brief  A class for comparing two histogram objects based on the average of the relative deviation between the bins
+///
+
+#ifndef QUALITYCONTROL_ObjectComparatorDeviation_H
+#define QUALITYCONTROL_ObjectComparatorDeviation_H
+
+#include "Common/ObjectComparatorInterface.h"
+
+namespace o2::quality_control_modules::common
+{
+
+/// \brief A class for comparing two histogram objects based on the average of the relative deviation between the bins
+class ObjectComparatorDeviation : public ObjectComparatorInterface
+{
+ public:
+  /// \brief Constructor
+  ObjectComparatorDeviation() = default;
+  /// \brief Destructor
+  virtual ~ObjectComparatorDeviation() = default;
+
+  /// \brief objects comparison function
+  /// \return the quality resulting from the object comparison
+  o2::quality_control::core::Quality compare(TObject* obj, TObject* objRef, std::string& message) override;
+};
+
+} // namespace o2::quality_control_modules::common
+
+#endif // QUALITYCONTROL_ObjectComparatorDeviation_H

Modules/Common/include/Common/ObjectComparatorInterface.h

@@ -0,0 +1,56 @@
+// Copyright 2019-2020 CERN and copyright holders of ALICE O2.
+// See https://alice-o2.web.cern.ch/copyright for details of the copyright holders.
+// All rights not expressly granted are reserved.
+//
+// This software is distributed under the terms of the GNU General Public
+// License v3 (GPL Version 3), copied verbatim in the file "COPYING".
+//
+// In applying this license CERN does not waive the privileges and immunities
+// granted to it by virtue of its status as an Intergovernmental Organization
+// or submit itself to any jurisdiction.
+
+///
+/// \file   ObjectComparatorInterface.h
+/// \author Andrea Ferrero
+/// \brief  An interface for comparing two TObject
+///
+
+#ifndef QUALITYCONTROL_ObjectComparatorInterface_H
+#define QUALITYCONTROL_ObjectComparatorInterface_H
+
+#include "QualityControl/Quality.h"
+#include "QualityControl/CustomParameters.h"
+#include "QualityControl/Activity.h"
+class TObject;
+
+namespace o2::quality_control_modules::common
+{
+
+/// \brief An interface for comparing two TObject
+class ObjectComparatorInterface
+{
+ public:
+  /// \brief Constructor
+  ObjectComparatorInterface() = default;
+  /// \brief Destructor
+  virtual ~ObjectComparatorInterface() = default;
+
+  /// \brief comparator configuration via CustomParameters
+  // virtual void configure(const o2::quality_control::core::CustomParameters& customParameters, const o2::quality_control::core::Activity activity = {}){};
+
+  /// setter/getter methods for the threshold to define the goodness of the comparison
+  void setThreshold(double threshold) { mThreshold = threshold; }
+  double getThreshold() { return mThreshold; }
+
+  /// \brief objects comparison function
+  /// \return the quality resulting from the object comparison
+  virtual o2::quality_control::core::Quality compare(TObject* obj, TObject* objRef, std::string& message) = 0;
+
+ private:
+  /// the threshold to define the goodness of the comparison
+  double mThreshold{ 0 };
+};
+
+} // namespace o2::quality_control_modules::common
+
+#endif // QUALITYCONTROL_ObjectComparatorInterface_H

Modules/Common/include/Common/ObjectComparatorKolmogorov.h

@@ -0,0 +1,42 @@
+// Copyright 2019-2020 CERN and copyright holders of ALICE O2.
+// See https://alice-o2.web.cern.ch/copyright for details of the copyright holders.
+// All rights not expressly granted are reserved.
+//
+// This software is distributed under the terms of the GNU General Public
+// License v3 (GPL Version 3), copied verbatim in the file "COPYING".
+//
+// In applying this license CERN does not waive the privileges and immunities
+// granted to it by virtue of its status as an Intergovernmental Organization
+// or submit itself to any jurisdiction.
+
+///
+/// \file   ObjectComparatorKolmogorov.h
+/// \author Andrea Ferrero
+/// \brief  A class for comparing two histogram objects based on a Kolmogorov test
+///
+
+#ifndef QUALITYCONTROL_ObjectComparatorKolmogorov_H
+#define QUALITYCONTROL_ObjectComparatorKolmogorov_H
+
+#include "Common/ObjectComparatorInterface.h"
+
+namespace o2::quality_control_modules::common
+{
+
+/// \brief A class for comparing two histogram objects based on a Kolmogorov test
+class ObjectComparatorKolmogorov : public ObjectComparatorInterface
+{
+ public:
+  /// \brief Constructor
+  ObjectComparatorKolmogorov() = default;
+  /// \brief Destructor
+  virtual ~ObjectComparatorKolmogorov() = default;
+
+  /// \brief objects comparison function
+  /// \return the quality resulting from the object comparison
+  o2::quality_control::core::Quality compare(TObject* obj, TObject* objRef, std::string& message) override;
+};
+
+} // namespace o2::quality_control_modules::common
+
+#endif // QUALITYCONTROL_ObjectComparatorKolmogorov_H

Modules/Common/include/Common/ReferenceComparatorCheck.h

@@ -0,0 +1,59 @@
+// Copyright 2019-2020 CERN and copyright holders of ALICE O2.
+// See https://alice-o2.web.cern.ch/copyright for details of the copyright holders.
+// All rights not expressly granted are reserved.
+//
+// This software is distributed under the terms of the GNU General Public
+// License v3 (GPL Version 3), copied verbatim in the file "COPYING".
+//
+// In applying this license CERN does not waive the privileges and immunities
+// granted to it by virtue of its status as an Intergovernmental Organization
+// or submit itself to any jurisdiction.
+
+///
+/// \file   ReferenceComparatorCheck.h
+/// \author Andrea Ferrero
+/// \brief  A generic QC check that compares a given set of histograms with their corresponding references
+///
+
+#ifndef QUALITYCONTROL_ReferenceComparatorCheck_H
+#define QUALITYCONTROL_ReferenceComparatorCheck_H
+
+#include "QualityControl/CheckInterface.h"
+#include "Common/ObjectComparatorInterface.h"
+
+#include <sstream>
+
+class TPaveText;
+
+namespace o2::quality_control_modules::common
+{
+
+/// \brief  A generic QC check that compares a given set of histograms with their corresponding references
+/// \author Andrea Ferrero
+class ReferenceComparatorCheck : public o2::quality_control::checker::CheckInterface
+{
+ public:
+  /// Default constructor
+  ReferenceComparatorCheck() = default;
+  /// Destructor
+  ~ReferenceComparatorCheck() override = default;
+
+  // Override interface
+  void configure() override;
+  Quality check(std::map<std::string, std::shared_ptr<MonitorObject>>* moMap) override;
+  void reset() override;
+  void beautify(std::shared_ptr<MonitorObject> mo, Quality checkResult = Quality::Null) override;
+  std::string getAcceptedType() override;
+
+  void startOfActivity(const Activity& activity) override;
+  void endOfActivity(const Activity& activity) override;
+
+ private:
+  std::unique_ptr<ObjectComparatorInterface> mComparator;
+  std::map<std::string, Quality> mQualityFlags;
+  std::map<std::string, std::shared_ptr<TPaveText>> mQualityLabels;
+};
+
+} // namespace o2::quality_control_modules::common
+
+#endif // QC_MODULE_SKELETON_ReferenceComparatorCheck_H