feat: HitSelector algorithm (#2731)

Needed for the GNN+CKF workflow

Examples/Algorithms/Utilities/CMakeLists.txt

@@ -5,6 +5,7 @@ add_library(
   src/TrajectoriesToPrototracks.cpp
   src/TrackSelectorAlgorithm.cpp
   src/TracksToTrajectories.cpp
+  src/HitSelector.cpp
   src/TracksToParameters.cpp)
 target_include_directories(
   ActsExamplesUtilities

Examples/Algorithms/Utilities/include/ActsExamples/Utilities/HitSelector.hpp

@@ -0,0 +1,50 @@
+// This file is part of the Acts project.
+//
+// Copyright (C) 2019-2023 CERN for the benefit of the Acts project
+//
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this
+// file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+#pragma once
+
+#include "Acts/TrackFinding/TrackSelector.hpp"
+#include "Acts/Utilities/Logger.hpp"
+#include "ActsExamples/EventData/SimHit.hpp"
+#include "ActsExamples/Framework/DataHandle.hpp"
+#include "ActsExamples/Framework/IAlgorithm.hpp"
+
+#include <cstddef>
+#include <limits>
+#include <string>
+
+namespace ActsExamples {
+
+/// Select tracks by applying some selection cuts.
+class HitSelector final : public IAlgorithm {
+ public:
+  struct Config {
+    /// Input track collection.
+    std::string inputHits;
+    /// Output track collection
+    std::string outputHits;
+
+    /// Time cut
+    double maxTime = std::numeric_limits<double>::max();
+  };
+
+  HitSelector(const Config& config, Acts::Logging::Level level);
+
+  ProcessCode execute(const AlgorithmContext& ctx) const final;
+
+  /// Get readonly access to the config parameters
+  const Config& config() const { return m_cfg; }
+
+ private:
+  Config m_cfg;
+
+  ReadDataHandle<SimHitContainer> m_inputHits{this, "InputHits"};
+  WriteDataHandle<SimHitContainer> m_outputHits{this, "OutputHits"};
+};
+
+}  // namespace ActsExamples

Examples/Algorithms/Utilities/src/HitSelector.cpp

@@ -0,0 +1,33 @@
+// This file is part of the Acts project.
+//
+// Copyright (C) 2019-2023 CERN for the benefit of the Acts project
+//
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this
+// file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+#include "ActsExamples/Utilities/HitSelector.hpp"
+
+ActsExamples::HitSelector::HitSelector(const Config& config,
+                                       Acts::Logging::Level level)
+    : IAlgorithm("HitSelector", level), m_cfg(config) {
+  m_inputHits.initialize(m_cfg.inputHits);
+  m_outputHits.initialize(m_cfg.outputHits);
+}
+
+ActsExamples::ProcessCode ActsExamples::HitSelector::execute(
+    const ActsExamples::AlgorithmContext& ctx) const {
+  const auto& hits = m_inputHits(ctx);
+  SimHitContainer selectedHits;
+
+  std::copy_if(hits.begin(), hits.end(),
+               std::inserter(selectedHits, selectedHits.begin()),
+               [&](const auto& hit) { return hit.time() < m_cfg.maxTime; });
+
+  ACTS_DEBUG("selected " << selectedHits.size() << " from " << hits.size()
+                         << " hits");
+
+  m_outputHits(ctx, std::move(selectedHits));
+
+  return {};
+}

Examples/Python/src/TruthTracking.cpp

@@ -17,6 +17,7 @@
 #include "ActsExamples/TruthTracking/TruthSeedingAlgorithm.hpp"
 #include "ActsExamples/TruthTracking/TruthTrackFinder.hpp"
 #include "ActsExamples/TruthTracking/TruthVertexFinder.hpp"
+#include "ActsExamples/Utilities/HitSelector.hpp"
 #include "ActsExamples/Utilities/Range.hpp"
 
 #include <array>
@@ -195,6 +196,9 @@ void addTruthTracking(Context& ctx) {
       ActsExamples::TruthSeedingAlgorithm, mex, "TruthSeedingAlgorithm",
       inputParticles, inputMeasurementParticlesMap, inputSpacePoints,
       outputParticles, outputSeeds, outputProtoTracks, deltaRMin, deltaRMax);
+
+  ACTS_PYTHON_DECLARE_ALGORITHM(ActsExamples::HitSelector, mex, "HitSelector",
+                                inputHits, outputHits, maxTime);
 }
 
 }  // namespace Acts::Python