feat: Dense MeasurementContainer for Examples

Core/include/Acts/EventData/SubspaceHelpers.hpp

@@ -28,7 +28,7 @@ inline static bool checkSubspaceIndices(const Container& container,
   if (subspaceSize > fullSize) {
     return false;
   }
-  if (container.size() != subspaceSize) {
+  if (static_cast<std::size_t>(container.size()) != subspaceSize) {
     return false;
   }
   for (auto it = container.begin(); it != container.end();) {
@@ -49,6 +49,7 @@ class SubspaceHelperBase {
  public:
   static constexpr std::size_t kFullSize = FullSize;
 
+  using FullVector = ActsVector<kFullSize>;
   using FullSquareMatrix = ActsSquareMatrix<kFullSize>;
 
   bool empty() const { return self().empty(); }
@@ -59,6 +60,19 @@ class SubspaceHelperBase {
   auto begin() const { return self().begin(); }
   auto end() const { return self().end(); }
 
+  template <typename indices_t>
+  bool contains(indices_t i) const {
+    return std::find(begin(), end(), static_cast<Derived::IndexType>(i)) !=
+           end();
+  }
+
+  template <typename indices_t>
+  std::size_t indexOf(indices_t i) const {
+    auto it = std::find(begin(), end(), static_cast<Derived::IndexType>(i));
+    assert(it != end());
+    return std::distance(begin(), it);
+  }
+
   FullSquareMatrix fullProjector() const {
     FullSquareMatrix result = FullSquareMatrix::Zero();
     for (auto [i, index] : enumerate(*this)) {
@@ -81,6 +95,33 @@ class SubspaceHelperBase {
     return matrixToBitset(fullProjector()).to_ullong();
   }
 
+  template <typename EigenDerived>
+  FullVector expandVector(
+      const Eigen::DenseBase<EigenDerived>& subspaceVector) const {
+    assert(static_cast<std::size_t>(subspaceVector.size()) == size() &&
+           "Invalid subspace vector size");
+    FullVector result = FullVector::Zero();
+    for (auto [i, index] : enumerate(*this)) {
+      result(index) = subspaceVector(i);
+    }
+    return result;
+  }
+
+  template <typename EigenDerived>
+  FullSquareMatrix expandMatrix(
+      const Eigen::DenseBase<EigenDerived>& subspaceMatrix) const {
+    assert(static_cast<std::size_t>(subspaceMatrix.rows()) == size() &&
+           static_cast<std::size_t>(subspaceMatrix.cols()) == size() &&
+           "Invalid subspace matrix size");
+    FullSquareMatrix result = FullSquareMatrix::Zero();
+    for (auto [i, indexI] : enumerate(*this)) {
+      for (auto [j, indexJ] : enumerate(*this)) {
+        result(indexI, indexJ) = subspaceMatrix(i, j);
+      }
+    }
+    return result;
+  }
+
  private:
   const Derived& self() const { return static_cast<const Derived&>(*this); }
 };
@@ -112,6 +153,8 @@ class VariableSubspaceHelper
   auto begin() const { return m_indices.begin(); }
   auto end() const { return m_indices.end(); }
 
+  const Container& indices() const { return m_indices; }
+
  private:
   Container m_indices;
 };
@@ -154,6 +197,8 @@ class FixedSubspaceHelper
   auto begin() const { return m_indices.begin(); }
   auto end() const { return m_indices.end(); }
 
+  const Container& indices() const { return m_indices; }
+
   Projector projector() const {
     Projector result = Projector::Zero();
     for (auto [i, index] : enumerate(*this)) {

Examples/Algorithms/Digitization/include/ActsExamples/Digitization/MeasurementCreation.hpp

@@ -1,6 +1,6 @@
 // This file is part of the Acts project.
 //
-// Copyright (C) 2021 CERN for the benefit of the Acts project
+// Copyright (C) 2021-2024 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
@@ -40,9 +40,10 @@ struct DigitizedParameters {
 ///
 /// To be used also by the e I/O system
 ///
-/// @return a variant measurement
-Measurement createMeasurement(const DigitizedParameters& dParams,
-                              const IndexSourceLink& isl) noexcept(false);
+/// @return the measurement proxy
+ActsExamples::VariableBoundMeasurementProxy createMeasurement(
+    MeasurementContainer& container, const DigitizedParameters& dParams,
+    const IndexSourceLink& isl) noexcept(false);
 
 /// Construct the constituents of a measurement.
 ///

Examples/Algorithms/Digitization/src/DigitizationAlgorithm.cpp

@@ -1,6 +1,6 @@
 // This file is part of the Acts project.
 //
-// Copyright (C) 2021 CERN for the benefit of the Acts project
+// Copyright (C) 2021-2024 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
@@ -268,8 +268,7 @@ ActsExamples::ProcessCode ActsExamples::DigitizationAlgorithm::execute(
             // be added at the end.
             sourceLinks.insert(sourceLinks.end(), sourceLink);
 
-            measurements.emplace_back(
-                createMeasurement(dParameters, sourceLink));
+            createMeasurement(measurements, dParameters, sourceLink);
             clusters.emplace_back(std::move(dParameters.cluster));
             // this digitization does hit merging so there can be more than one
             // mapping entry for each digitized hit.

Examples/Algorithms/Digitization/src/MeasurementCreation.cpp

@@ -1,43 +1,41 @@
 // This file is part of the Acts project.
 //
-// Copyright (C) 2021 CERN for the benefit of the Acts project
+// Copyright (C) 2021-2024 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/Digitization/MeasurementCreation.hpp"
 
+#include "Acts/EventData/MeasurementHelpers.hpp"
 #include "Acts/EventData/SourceLink.hpp"
 #include "ActsExamples/EventData/IndexSourceLink.hpp"
+#include "ActsExamples/EventData/Measurement.hpp"
 
 #include <stdexcept>
 #include <string>
 #include <utility>
 
-ActsExamples::Measurement ActsExamples::createMeasurement(
-    const DigitizedParameters& dParams, const IndexSourceLink& isl) {
+ActsExamples::VariableBoundMeasurementProxy ActsExamples::createMeasurement(
+    MeasurementContainer& container, const DigitizedParameters& dParams,
+    const IndexSourceLink& isl) {
   Acts::SourceLink sl{isl};
-  switch (dParams.indices.size()) {
-    case 1u: {
-      auto [indices, par, cov] = measurementConstituents<1>(dParams);
-      return ActsExamples::Measurement(std::move(sl), indices, par, cov);
-    }
-    case 2u: {
-      auto [indices, par, cov] = measurementConstituents<2>(dParams);
-      return ActsExamples::Measurement(std::move(sl), indices, par, cov);
-    };
-    case 3u: {
-      auto [indices, par, cov] = measurementConstituents<3>(dParams);
-      return ActsExamples::Measurement(std::move(sl), indices, par, cov);
-    };
-    case 4u: {
-      auto [indices, par, cov] = measurementConstituents<4>(dParams);
-      return ActsExamples::Measurement(std::move(sl), indices, par, cov);
-    };
-    default:
-      std::string errorMsg = "Invalid/mismatching measurement dimension: " +
-                             std::to_string(dParams.indices.size());
-      throw std::runtime_error(errorMsg.c_str());
+
+  if (dParams.indices.size() > 4u) {
+    std::string errorMsg = "Invalid/mismatching measurement dimension: " +
+                           std::to_string(dParams.indices.size());
+    throw std::runtime_error(errorMsg.c_str());
   }
+
+  return Acts::visit_measurement(
+      dParams.indices.size(), [&](auto dim) -> VariableBoundMeasurementProxy {
+        auto [indices, par, cov] = measurementConstituents<dim>(dParams);
+        FixedBoundMeasurementProxy<dim> measurement =
+            container.makeMeasurement<dim>();
+        measurement.setSubspaceIndices(indices);
+        measurement.parameters() = par;
+        measurement.covariance() = cov;
+        return measurement;
+      });
 }

Examples/Algorithms/TrackFinding/src/HoughTransformSeeder.cpp

@@ -525,7 +525,8 @@ void ActsExamples::HoughTransformSeeder::addMeasurements(
         // are transformed to the bound space where we do know their location.
         // if the local parameters are not measured, this results in a
         // zero location, which is a reasonable default fall-back.
-        const auto& measurement = measurements[sourceLink.index()];
+        const ConstVariableBoundMeasurementProxy measurement =
+            measurements.getMeasurement(sourceLink.index());
 
         assert(measurement.contains(Acts::eBoundLoc0) &&
                "Measurement does not contain the required bound loc0");

Examples/Algorithms/TrackFinding/src/SpacePointMaker.cpp

@@ -126,7 +126,8 @@ ActsExamples::ProcessCode ActsExamples::SpacePointMaker::execute(
 
   spOpt.paramCovAccessor = [&measurements](Acts::SourceLink slink) {
     const auto islink = slink.get<IndexSourceLink>();
-    const auto& meas = measurements[islink.index()];
+    const ConstVariableBoundMeasurementProxy meas =
+        measurements.getMeasurement(islink.index());
 
     return std::make_pair(meas.fullParameters(), meas.fullCovariance());
   };

Examples/Framework/CMakeLists.txt

@@ -5,6 +5,7 @@ set(ActsExamplesFramework_SOURCES)
 add_library(
     ActsExamplesFramework
     SHARED
+    src/EventData/Measurement.cpp
     src/EventData/MeasurementCalibration.cpp
     src/EventData/ScalingCalibrator.cpp
     src/Framework/IAlgorithm.cpp