refactor: Track Finding and Fitting algorithms output Tracks only (#1858

)

This removes the `Trajectories` output writing, completely moving to the separate conversion algorithm introduced in #1857

Blocked by:
- #1854
- #1839 
- #1857

Examples/Algorithms/TrackFinding/include/ActsExamples/TrackFinding/TrackFindingAlgorithm.hpp

@@ -67,8 +67,6 @@ class TrackFindingAlgorithm final : public BareAlgorithm {
     /// Input initial track parameter estimates for for each proto track.
     std::string inputInitialTrackParameters;
     /// Output find trajectories collection.
-    std::string outputTrajectories;
-    /// Output find tracks collection.
     std::string outputTracks;
     /// Type erased track finder function.
     std::shared_ptr<TrackFinderFunction> findTracks;

Examples/Algorithms/TrackFinding/src/TrackFindingAlgorithm.cpp

@@ -9,14 +9,14 @@
 #include "ActsExamples/TrackFinding/TrackFindingAlgorithm.hpp"
 
 #include "Acts/EventData/MultiTrajectory.hpp"
+#include "Acts/EventData/Track.hpp"
 #include "Acts/EventData/VectorMultiTrajectory.hpp"
 #include "Acts/EventData/VectorTrackContainer.hpp"
 #include "Acts/Surfaces/PerigeeSurface.hpp"
 #include "Acts/TrackFitting/GainMatrixSmoother.hpp"
 #include "Acts/TrackFitting/GainMatrixUpdater.hpp"
 #include "ActsExamples/EventData/Measurement.hpp"
 #include "ActsExamples/EventData/Track.hpp"
-#include "ActsExamples/EventData/Trajectories.hpp"
 #include "ActsExamples/Framework/ProcessCode.hpp"
 #include "ActsExamples/Framework/WhiteBoard.hpp"
 
@@ -39,9 +39,6 @@ ActsExamples::TrackFindingAlgorithm::TrackFindingAlgorithm(
     throw std::invalid_argument(
         "Missing initial track parameters input collection");
   }
-  if (m_cfg.outputTrajectories.empty()) {
-    throw std::invalid_argument("Missing trajectories output collection");
-  }
   if (m_cfg.outputTracks.empty()) {
     throw std::invalid_argument("Missing tracks output collection");
   }
@@ -57,11 +54,6 @@ ActsExamples::ProcessCode ActsExamples::TrackFindingAlgorithm::execute(
   const auto& initialParameters = ctx.eventStore.get<TrackParametersContainer>(
       m_cfg.inputInitialTrackParameters);
 
-  // Prepare the output data with MultiTrajectory
-  // @TODO: Refactor to remove Trajectories
-  TrajectoriesContainer trajectories;
-  trajectories.reserve(initialParameters.size());
-
   // Construct a perigee surface as the target surface
   auto pSurface = Acts::Surface::makeShared<Acts::PerigeeSurface>(
       Acts::Vector3{0., 0., 0.});
@@ -107,51 +99,41 @@ ActsExamples::ProcessCode ActsExamples::TrackFindingAlgorithm::execute(
 
   TrackContainer tracks(trackContainer, trackStateContainer);
 
+  tracks.addColumn<unsigned int>("trackGroup");
+  Acts::TrackAccessor<unsigned int> seedNumber("trackGroup");
+
+  unsigned int nSeed = 0;
+
   for (std::size_t iseed = 0; iseed < initialParameters.size(); ++iseed) {
     auto result =
         (*m_cfg.findTracks)(initialParameters.at(iseed), options, tracks);
     m_nTotalSeeds++;
+    nSeed++;
+
     if (!result.ok()) {
       m_nFailedSeeds++;
       ACTS_WARNING("Track finding failed for seed " << iseed << " with error"
                                                     << result.error());
-      // Track finding failed. Add an empty result so the output container has
-      // the same number of entries as the input.
-      trajectories.push_back(Trajectories());
       continue;
     }
 
     auto& tracksForSeed = result.value();
-    std::vector<Acts::MultiTrajectoryTraits::IndexType> tips;
-    tips.reserve(tracksForSeed.size());
-    Trajectories::IndexedParameters parameters;
-    parameters.reserve(tracksForSeed.size());
-
     for (auto& track : tracksForSeed) {
-      tips.push_back(track.tipIndex());
-      parameters.emplace(
-          std::pair{track.tipIndex(),
-                    TrackParameters{track.referenceSurface().getSharedPtr(),
-                                    track.parameters(), track.covariance()}});
+      seedNumber(track) = nSeed;
     }
-
-    // Create a Trajectories result struct
-    trajectories.emplace_back(*trackStateContainer, std::move(tips),
-                              std::move(parameters));
   }
 
   // Compute shared hits from all the reconstructed tracks
   if (m_cfg.computeSharedHits) {
     computeSharedHits(sourceLinks, tracks);
   }
 
-  ACTS_DEBUG("Finalized track finding with " << trajectories.size()
+  ACTS_DEBUG("Finalized track finding with " << tracks.size()
                                              << " track candidates.");
 
   m_memoryStatistics.local().hist +=
       tracks.trackStateContainer().statistics().hist;
 
-  ctx.eventStore.add(m_cfg.outputTrajectories, std::move(trajectories));
   ctx.eventStore.add(m_cfg.outputTracks, std::move(tracks));
   return ActsExamples::ProcessCode::SUCCESS;
 }

Examples/Algorithms/TrackFitting/include/ActsExamples/TrackFitting/TrackFittingAlgorithm.hpp

@@ -81,8 +81,6 @@ class TrackFittingAlgorithm final : public BareAlgorithm {
     std::string inputProtoTracks;
     /// Input initial track parameter estimates for for each proto track.
     std::string inputInitialTrackParameters;
-    /// Output fitted trajectories collection.
-    std::string outputTrajectories;
     /// Output fitted tracks collection.
     std::string outputTracks;
     /// Type erased fitter function.

Examples/Algorithms/TrackFitting/src/TrackFittingAlgorithm.cpp

@@ -13,7 +13,6 @@
 #include "Acts/TrackFitting/GainMatrixSmoother.hpp"
 #include "Acts/TrackFitting/GainMatrixUpdater.hpp"
 #include "ActsExamples/EventData/ProtoTrack.hpp"
-#include "ActsExamples/EventData/Trajectories.hpp"
 #include "ActsExamples/Framework/WhiteBoard.hpp"
 
 #include <stdexcept>
@@ -38,9 +37,6 @@ ActsExamples::TrackFittingAlgorithm::TrackFittingAlgorithm(
   if (not m_cfg.trackingGeometry) {
     throw std::invalid_argument("Missing tracking geometry");
   }
-  if (m_cfg.outputTrajectories.empty()) {
-    throw std::invalid_argument("Missing output trajectories collection");
-  }
   if (m_cfg.outputTracks.empty()) {
     throw std::invalid_argument("Missing output tracks collection");
   }
@@ -64,10 +60,6 @@ ActsExamples::ProcessCode ActsExamples::TrackFittingAlgorithm::execute(
     return ProcessCode::ABORT;
   }
 
-  // Prepare the output data with MultiTrajectory
-  TrajectoriesContainer trajectories;
-  trajectories.reserve(protoTracks.size());
-
   // Construct a perigee surface as the target surface
   auto pSurface = Acts::Surface::makeShared<Acts::PerigeeSurface>(
       Acts::Vector3{0., 0., 0.});
@@ -101,7 +93,6 @@ ActsExamples::ProcessCode ActsExamples::TrackFittingAlgorithm::execute(
     // We can have empty tracks which must give empty fit results so the number
     // of entries in input and output containers matches.
     if (protoTrack.empty()) {
-      trajectories.push_back(Trajectories());
       ACTS_WARNING("Empty track " << itrack << " found.");
       continue;
     }
@@ -139,42 +130,24 @@ ActsExamples::ProcessCode ActsExamples::TrackFittingAlgorithm::execute(
 
     if (result.ok()) {
       // Get the fit output object
-      auto& track = result.value();
-      // The track entry indices container. One element here.
-      std::vector<Acts::MultiTrajectoryTraits::IndexType> trackTips;
-      trackTips.reserve(1);
-      trackTips.emplace_back(track.tipIndex());
-      // The fitted parameters container. One element (at most) here.
-      Trajectories::IndexedParameters indexedParams;
+      const auto& track = result.value();
       if (track.hasReferenceSurface()) {
         ACTS_VERBOSE("Fitted parameters for track " << itrack);
         ACTS_VERBOSE("  " << track.parameters().transpose());
-        // Push the fitted parameters to the container
-        indexedParams.emplace(
-            std::pair{track.tipIndex(),
-                      TrackParameters{track.referenceSurface().getSharedPtr(),
-                                      track.parameters(), track.covariance()}});
       } else {
         ACTS_DEBUG("No fitted parameters for track " << itrack);
       }
-      // store the result
-      trajectories.emplace_back(*trackStateContainer, std::move(trackTips),
-                                std::move(indexedParams));
     } else {
       ACTS_WARNING("Fit failed for track "
                    << itrack << " with error: " << result.error() << ", "
                    << result.error().message());
-      // Fit failed. Add an empty result so the output container has
-      // the same number of entries as the input.
-      trajectories.push_back(Trajectories());
     }
   }
 
   std::stringstream ss;
   trackStateContainer->statistics().toStream(ss);
   ACTS_DEBUG(ss.str());
 
-  ctx.eventStore.add(m_cfg.outputTrajectories, std::move(trajectories));
   ctx.eventStore.add(m_cfg.outputTracks, std::move(tracks));
   return ActsExamples::ProcessCode::SUCCESS;
 }

Examples/Algorithms/TrackFittingChi2/include/ActsExamples/TrackFittingChi2/TrackFittingChi2Algorithm.hpp

@@ -59,8 +59,6 @@ class TrackFittingChi2Algorithm final : public BareAlgorithm {
     /// Input initial track parameter estimates for for each proto track.
     std::string inputInitialTrackParameters;
     /// Output fitted trajectories collection.
-    std::string outputTrajectories;
-    /// Output fitted tracks collection.
     std::string outputTracks;
     /// number of update steps
     unsigned int nUpdates = 0;

Examples/Algorithms/TrackFittingChi2/src/TrackFittingChi2Algorithm.cpp

@@ -11,7 +11,6 @@
 #include "Acts/EventData/Track.hpp"
 #include "Acts/Surfaces/PerigeeSurface.hpp"
 #include "ActsExamples/EventData/ProtoTrack.hpp"
-#include "ActsExamples/EventData/Trajectories.hpp"
 #include "ActsExamples/Framework/WhiteBoard.hpp"
 
 #include <stdexcept>
@@ -36,9 +35,6 @@ ActsExamples::TrackFittingChi2Algorithm::TrackFittingChi2Algorithm(
   if (not m_cfg.trackingGeometry) {
     throw std::invalid_argument("Missing tracking geometry");
   }
-  if (m_cfg.outputTrajectories.empty()) {
-    throw std::invalid_argument("Missing output trajectories collection");
-  }
   if (m_cfg.outputTracks.empty()) {
     throw std::invalid_argument("Missing output track collection");
   }
@@ -62,10 +58,6 @@ ActsExamples::ProcessCode ActsExamples::TrackFittingChi2Algorithm::execute(
     return ProcessCode::ABORT;
   }
 
-  // Prepare the output data with MultiTrajectory
-  TrajectoriesContainer trajectories;
-  trajectories.reserve(protoTracks.size());
-
   // Set Chi2 options
   Acts::Experimental::Chi2FitterExtensions<Acts::VectorMultiTrajectory>
       extensions;
@@ -86,6 +78,7 @@ ActsExamples::ProcessCode ActsExamples::TrackFittingChi2Algorithm::execute(
   TrackContainer tracks(trackContainer, trackStateContainer);
 
   tracks.addColumn<Acts::ActsScalar>("chi2");
+
   static Acts::ConstTrackAccessor<Acts::ActsScalar> chisquare{"chi2"};
 
   // Perform the fit for each input track
@@ -104,7 +97,6 @@ ActsExamples::ProcessCode ActsExamples::TrackFittingChi2Algorithm::execute(
     // We can have empty tracks which must give empty fit results so the number
     // of entries in input and output containers matches.
     if (protoTrack.empty()) {
-      trajectories.push_back(Trajectories());
       ACTS_WARNING("Empty track " << itrack << " found.");
       continue;
     }
@@ -138,41 +130,23 @@ ActsExamples::ProcessCode ActsExamples::TrackFittingChi2Algorithm::execute(
     if (result.ok()) {
       ACTS_DEBUG("result ok");
       // Get the fit output object
-      auto& track = result.value();
-      // The track entry indices container. One element here.
-      std::vector<Acts::MultiTrajectoryTraits::IndexType> trackTips;
-      trackTips.reserve(1);
-      trackTips.emplace_back(track.tipIndex());
-      // The fitted parameters container. One element (at most) here.
-      Trajectories::IndexedParameters indexedParams;
+      const auto& track = result.value();
       ACTS_VERBOSE("final χ² = " << chisquare(track));
       ACTS_VERBOSE("lastMeasurementIndex = " << track.tipIndex());
 
       if (track.hasReferenceSurface()) {
         ACTS_VERBOSE("Fitted parameters for track "
                      << itrack << ": " << track.parameters().transpose());
-        // Push the fitted parameters to the container
-        indexedParams.emplace(
-            std::pair{track.tipIndex(),
-                      TrackParameters{track.referenceSurface().getSharedPtr(),
-                                      track.parameters(), track.covariance()}});
       } else {
         ACTS_DEBUG("No fitted parameters for track " << itrack);
       }
-      // store the result
-      trajectories.emplace_back(*trackStateContainer, std::move(trackTips),
-                                std::move(indexedParams));
     } else {
       ACTS_WARNING("Fit failed for track "
                    << itrack << " with error: " << result.error() << ", "
                    << result.error().message());
-      // Fit failed. Add an empty result so the output container has
-      // the same number of entries as the input.
-      trajectories.push_back(Trajectories());
     }
   }
 
-  ctx.eventStore.add(m_cfg.outputTrajectories, std::move(trajectories));
   ctx.eventStore.add(m_cfg.outputTracks, std::move(tracks));
   // TODO: add chi2 values as output?
   return ActsExamples::ProcessCode::SUCCESS;

Examples/Python/python/acts/examples/reconstruction.py

@@ -773,7 +773,6 @@ def addKalmanTracks(
         inputSourceLinks="sourcelinks",
         inputProtoTracks=inputProtoTracks,
         inputInitialTrackParameters="estimatedparameters",
-        outputTrajectories="kfTrajectories",
         outputTracks="kfTracks",
         directNavigation=directNavigation,
         pickTrack=-1,
@@ -784,7 +783,14 @@ def addKalmanTracks(
     )
     s.addAlgorithm(fitAlg)
 
-    s.addWhiteboardAlias("trajectories", fitAlg.config.outputTrajectories)
+    trackConverter = acts.examples.TracksToTrajectories(
+        level=customLogLevel(),
+        inputTracks=fitAlg.config.outputTracks,
+        outputTrajectories="kfTrajectories",
+    )
+    s.addAlgorithm(trackConverter)
+
+    s.addWhiteboardAlias("trajectories", trackConverter.config.outputTrajectories)
 
     return s
 
@@ -814,16 +820,21 @@ def addTruthTrackingGsf(
         inputSourceLinks="sourcelinks",
         inputProtoTracks="prototracks",
         inputInitialTrackParameters="estimatedparameters",
-        outputTrajectories="gsf_trajectories",
         outputTracks="gsf_tracks",
         directNavigation=False,
         pickTrack=-1,
         trackingGeometry=trackingGeometry,
         fit=acts.examples.makeGsfFitterFunction(trackingGeometry, field, **gsfOptions),
     )
-
     s.addAlgorithm(gsfAlg)
 
+    trackConverter = acts.examples.TracksToTrajectories(
+        level=customLogLevel(),
+        inputTracks=gsfAlg.config.outputTracks,
+        outputTrajectories="gsf_trajectories",
+    )
+    s.addAlgorithm(trackConverter)
+
     return s
 
 
@@ -880,21 +891,27 @@ def addCKFTracks(
         inputMeasurements="measurements",
         inputSourceLinks="sourcelinks",
         inputInitialTrackParameters="estimatedparameters",
-        outputTrajectories="ckfTrajectories",
         outputTracks="ckfTracks",
         findTracks=acts.examples.TrackFindingAlgorithm.makeTrackFinderFunction(
             trackingGeometry, field
         ),
     )
     s.addAlgorithm(trackFinder)
 
-    s.addWhiteboardAlias("trajectories", trackFinder.config.outputTrajectories)
+    trackConverter = acts.examples.TracksToTrajectories(
+        level=customLogLevel(),
+        inputTracks=trackFinder.config.outputTracks,
+        outputTrajectories="trajectories-from-tracks",
+    )
+    s.addAlgorithm(trackConverter)
+
+    s.addWhiteboardAlias("trajectories", trackConverter.config.outputTrajectories)
 
     if trackSelectorRanges is not None:
         trackSelector = addTrackSelection(
             s,
             trackSelectorRanges,
-            inputTrajectories=trackFinder.config.outputTrajectories,
+            inputTrajectories=trackConverter.config.outputTrajectories,
             outputTrajectories="selectedTrajectories",
             logLevel=customLogLevel(),
         )
@@ -904,7 +921,7 @@ def addCKFTracks(
     addTrajectoryWriters(
         s,
         name="ckf",
-        trajectories=trackFinder.config.outputTrajectories,
+        trajectories=trackConverter.config.outputTrajectories,
         ckfPerformanceConfig=ckfPerformanceConfig,
         outputDirCsv=outputDirCsv,
         outputDirRoot=outputDirRoot,

Examples/Python/src/TrackFinding.cpp

@@ -263,7 +263,6 @@ void addTrackFinding(Context& ctx) {
     ACTS_PYTHON_MEMBER(inputMeasurements);
     ACTS_PYTHON_MEMBER(inputSourceLinks);
     ACTS_PYTHON_MEMBER(inputInitialTrackParameters);
-    ACTS_PYTHON_MEMBER(outputTrajectories);
     ACTS_PYTHON_MEMBER(outputTracks);
     ACTS_PYTHON_MEMBER(findTracks);
     ACTS_PYTHON_MEMBER(measurementSelectorCfg);