Add datatypes for storing generator (meta)data in a structured and defined way

README.md

@@ -39,11 +39,18 @@ A generic event data model for future HEP collider experiments.
 | [MCRecoTrackerHitPlaneAssociation](https://github.com/key4hep/EDM4hep/blob/main/edm4hep.yaml#L641) | [MCRecoCaloParticleAssociation](https://github.com/key4hep/EDM4hep/blob/main/edm4hep.yaml#L650) | [MCRecoClusterParticleAssociation](https://github.com/key4hep/EDM4hep/blob/main/edm4hep.yaml#L659) |
 | [MCRecoTrackParticleAssociation](https://github.com/key4hep/EDM4hep/blob/main/edm4hep.yaml#L668)   | [RecoParticleVertexAssociation](https://github.com/key4hep/EDM4hep/blob/main/edm4hep.yaml#L677) |                                                                                                      |
 
+**Generator related (meta-)data**
+
+| | | |
+|-|-|-|
+| [GeneratorParameters](https://github.com/key4hep/EDM4hep/blob/main/edm4hep.yaml#L787) | | |
+| [GeneratorPdfInfo](https://github.com/key4hep/EDM4hep/blob/main/edm4hep.yaml#L801) | | |
+
 **Interfaces**
 
 | | | |
 |-|-|-|
-| [TrackerHit](https://github.com/key4hep/EDM4hep/blob/main/edm4hep.yaml#L784) | | |
+| [TrackerHit](https://github.com/key4hep/EDM4hep/blob/main/edm4hep.yaml#L813) | | |
 
 
 The tests and examples in the `tests` directory show how to read, write, and use these types in your code.

edm4hep.yaml

@@ -780,6 +780,36 @@ datatypes:
     OneToOneRelations:
       - edm4hep::Track track           // the corresponding track
 
+
+  #===== Generator related data =====
+
+  #---------- GeneratorParameters
+  edm4hep::GeneratorParameters:
+    Description: "Generator parameters"
+    Author: "EDM4hep authors"
+    Members:
+      - double event_scale              // event scale
+      - double alphaQED                 // alpha_QED
+      - double alphaQCD                 // alpha_QCD
+      - int signal_process_id           // id of signal process
+      - double sqrt_s  [GeV]            // sqrt(s)
+    VectorMembers:
+      - double crossSections            // list of cross sections in pb
+      - double crossSectionErrors       // list of cross section errors
+
+  #---------- GeneratorPdfInfo
+  edm4hep::GeneratorPdfInfo:
+    Description: "Generator pdf information"
+    Author: "EDM4hep authors"
+    Members:
+      - std::array<int, 2> parton_id      // Parton PDG id
+      - std::array<int, 2> id             // LHAPDF PDF id (see https://lhapdf.hepforge.org/pdfsets.html)
+      - std::array<double, 2> x           // Parton momentum fraction
+      - std::array<double, 2> xf          // PDF value
+      - double scale [GeV]                // Factorisation scale
+    OneToManyRelations:
+      - edm4hep::MCParticle signal_vertex // pointing into MC Generators collection
+
 interfaces:
   edm4hep::TrackerHit:
     Description: "Tracker hit interface class"

include/edm4hep/GenToolInfo.h

@@ -0,0 +1,47 @@
+#ifndef EDM4HEP_GENTOOLINFO_H
+#define EDM4HEP_GENTOOLINFO_H
+
+#include "podio/Frame.h"
+#include "Constants.h"
+#include <string>
+#include <vector>
+
+namespace edm4hep {
+
+struct GenToolInfo {
+  std::string name;
+  std::string version;
+  std::string description;
+};
+
+const std::vector<GenToolInfo> getGenToolInfos(podio::Frame& frame) {
+  auto toolInfos = std::vector<GenToolInfo>();
+  auto names = frame.getParameter<std::string>("name");
+  auto versions = frame.getParameter<std::string>("version");
+  auto descriptions = frame.getParameter<std::string>("description");
+  for (unsigned int i = 0; i < names.size(); ++i) {
+    auto toolInfo = GenToolInfo();
+    toolInfo.name = names[i];
+    toolInfo.version = versions[i];
+    toolInfo.description = descriptions[i];
+  }
+  return toolInfos;
+};
+
+void putGenToolInfos(podio::Frame& frame, std::vector<GenToolInfo>& toolInfos) {
+  auto names = std::vector<std::string>();
+  auto versions = std::vector<std::string>();
+  auto descriptions = std::vector<std::string>();
+  for (auto& toolInfo : toolInfos){
+    names.push_back(toolInfo.name);
+    versions.push_back(toolInfo.version);
+    descriptions.push_back(toolInfo.description);
+  }
+  frame.putParameter("name", names);
+  frame.putParameter("version", versions);
+  frame.putParameter("description", descriptions);
+};
+
+} // namespace edm4hep
+
+#endif // EDM4HEP_GENTOOLINFO_H

test/write_events.h

@@ -2,7 +2,11 @@
 #define EDM4HEP_TEST_WRITE_EVENTS_H
 
 // Data model
+
 #include "edm4hep/CaloHitContributionCollection.h"
+#include "edm4hep/GenToolInfo.h"
+#include "edm4hep/GeneratorParametersCollection.h"
+#include "edm4hep/GeneratorPdfInfoCollection.h"
 #include "edm4hep/MCParticleCollection.h"
 #include "edm4hep/RawTimeSeriesCollection.h"
 #include "edm4hep/SimCalorimeterHitCollection.h"
@@ -28,6 +32,7 @@ void write(std::string outfilename) {
   for (unsigned i = 0; i < nevents; ++i) {
     std::cout << " --- processing event " << i << std::endl;
     auto event = podio::Frame();
+    auto run = podio::Frame();
 
     // place the following generator event to the MCParticle collection
     //
@@ -108,6 +113,40 @@ void write(std::string outfilename) {
       }
     }
 
+    //===============================================================================
+    // write some generator event data
+    auto genParametersCollection = edm4hep::GeneratorParametersCollection();
+    auto genParam = genParametersCollection.create();
+    genParam.setEvent_scale(23);
+    genParam.setAlphaQED(1 / 127);
+    genParam.setAlphaQCD(0.1);
+    genParam.setSignal_process_id(42);
+    genParam.setSqrt_s(90);
+    genParam.addToCrossSections(10);
+    genParam.addToCrossSectionErrors(3);
+    event.put(std::move(genParametersCollection), "GeneratorParameters");
+
+    auto genPdfInfoCollection = edm4hep::GeneratorPdfInfoCollection();
+    auto genPdfInfo = genPdfInfoCollection.create();
+    genPdfInfo.setParton_id(1, 2);
+    genPdfInfo.setId({20, 20});
+    genPdfInfo.setX({0.5, 0.5});
+    genPdfInfo.setXf({0.5, 0.5});
+    genPdfInfo.setScale(23);
+    genPdfInfo.addToSignal_vertex(mcp1);
+    genPdfInfo.addToSignal_vertex(mcp2);
+    event.put(std::move(genPdfInfoCollection), "GeneratorPdfInfo");
+
+    //===============================================================================
+    // write some generator tool info into the run
+    auto toolInfos = std::vector<edm4hep::GenToolInfo>();
+    auto toolInfo = edm4hep::GenToolInfo();
+    toolInfo.name = "something";
+    toolInfo.version = "v1";
+    toolInfo.description = "some tool";
+    toolInfos.emplace_back(std::move(toolInfo));
+    edm4hep::putGenToolInfos(run, toolInfos);
+
     // fixme: should this become a utility function ?
     //-------------------------------------------------------------
 
@@ -237,6 +276,7 @@ void write(std::string outfilename) {
     event.putParameter("EventType", "test");
 
     writer.writeFrame(event, "events");
+    writer.writeFrame(run, "runs");
   }
 
   writer.finish();

tools/include/edm4hep2json.hxx

@@ -6,6 +6,8 @@
 #include "edm4hep/CalorimeterHitCollection.h"
 #include "edm4hep/ClusterCollection.h"
 #include "edm4hep/EventHeaderCollection.h"
+#include "edm4hep/GeneratorParametersCollection.h"
+#include "edm4hep/GeneratorPdfInfoCollection.h"
 #include "edm4hep/MCParticleCollection.h"
 #include "edm4hep/ParticleIDCollection.h"
 #include "edm4hep/RawCalorimeterHitCollection.h"
@@ -154,6 +156,12 @@ nlohmann::json processEvent(const podio::Frame& frame, std::vector<std::string>&
       insertIntoJson<podio::UserDataCollection<uint32_t>>(jsonDict, coll, collList[i]);
     } else if (coll->getTypeName() == "podio::UserDataCollection<uint64_t>") {
       insertIntoJson<podio::UserDataCollection<uint64_t>>(jsonDict, coll, collList[i]);
+    }
+    // Generator (meta-)data
+    else if (coll->getTypeName() == "podio::GeneratorParametersCollection") {
+      insertIntoJson<edm4hep::GeneratorParametersCollection>(jsonDict, coll, collList[i]);
+    } else if (coll->getTypeName() == "podio::GeneratorPdfInfoCollection") {
+      insertIntoJson<edm4hep::GeneratorPdfInfoCollection>(jsonDict, coll, collList[i]);
     } else {
       std::cout << "WARNING: Collection type not recognized!\n"
                 << "         " << coll->getTypeName() << "\n";