refactor: set full vertex covariance after seeding

Core/include/Acts/Vertexing/AdaptiveGridDensityVertexFinder.hpp

@@ -1,6 +1,6 @@
 // This file is part of the Acts project.
 //
-// Copyright (C) 2020 CERN for the benefit of the Acts project
+// Copyright (C) 2020-2023 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
@@ -33,22 +33,31 @@ namespace Acts {
 /// @tparam trkGridSize The 2-dim grid size of a single track, i.e.
 /// a single track is modelled as a (trkGridSize x trkGridSize) grid
 /// in the d0-z0 plane. Note: trkGridSize has to be an odd value.
-template <int trkGridSize = 15, typename vfitter_t = DummyVertexFitter<>>
+template <int spatialTrkGridSize = 15, int temporalTrkGridSize = 1,
+          typename vfitter_t = DummyVertexFitter<>>
 class AdaptiveGridDensityVertexFinder {
-  // Assert odd trkGridSize
-  static_assert(trkGridSize % 2);
+  // Assert odd grid sizes
+  static_assert(spatialTrkGridSize % 2);
+  static_assert(temporalTrkGridSize % 2);
 
   using InputTrack_t = typename vfitter_t::InputTrack_t;
-  using GridDensity = AdaptiveGridTrackDensity<trkGridSize>;
+  using GridDensity =
+      AdaptiveGridTrackDensity<spatialTrkGridSize, temporalTrkGridSize>;
 
  public:
   using DensityMap = typename GridDensity::DensityMap;
 
   /// @brief The Config struct
   struct Config {
-    ///@param binSize Bin size of grid in mm
-    Config(float binSize = 0.1)
-        : gridDensity(typename GridDensity::Config(binSize)) {}
+    /// @param spatialBinExtent_ The spatial extent of a bin in mm
+    Config(float spatialBinExtent = 0.1)
+        : gridDensity(typename GridDensity::Config(spatialBinExtent)) {}
+    /// @param spatialBinExtent_ The spatial extent of a bin in mm
+    /// @param temporalBinExtent_ The temporal extent of a bin in mm
+    /// @note The speed of light is set to 1, hence the unit.
+    Config(float spatialBinExtent, float temporalBinExtent)
+        : gridDensity(typename GridDensity::Config(spatialBinExtent,
+                                                   temporalBinExtent)) {}
     ///@param gDensity The grid density
     Config(const GridDensity& gDensity) : gridDensity(gDensity) {}
 

Core/include/Acts/Vertexing/AdaptiveGridDensityVertexFinder.ipp

@@ -1,15 +1,17 @@
 // This file is part of the Acts project.
 //
-// Copyright (C) 2020 CERN for the benefit of the Acts project
+// Copyright (C) 2020-2023 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/.
 
-template <int trkGridSize, typename vfitter_t>
-auto Acts::AdaptiveGridDensityVertexFinder<trkGridSize, vfitter_t>::find(
-    const std::vector<const InputTrack_t*>& trackVector,
-    const VertexingOptions<InputTrack_t>& vertexingOptions, State& state) const
+template <int spatialTrkGridSize, int temporalTrkGridSize, typename vfitter_t>
+auto Acts::AdaptiveGridDensityVertexFinder<
+    spatialTrkGridSize, temporalTrkGridSize,
+    vfitter_t>::find(const std::vector<const InputTrack_t*>& trackVector,
+                     const VertexingOptions<InputTrack_t>& vertexingOptions,
+                     State& state) const
     -> Result<std::vector<Vertex<InputTrack_t>>> {
   // Remove density contributions from tracks removed from track collection
   if (m_cfg.cacheGridStateForTrackRemoval && state.isInitialized &&
@@ -56,7 +58,8 @@ auto Acts::AdaptiveGridDensityVertexFinder<trkGridSize, vfitter_t>::find(
   }
 
   double z = 0;
-  double width = 0;
+  double t = 0;
+  double zWidth = 0;
   if (!state.mainDensityMap.empty()) {
     if (!m_cfg.estimateSeedWidth) {
       // Get z value of highest density bin
@@ -66,6 +69,7 @@ auto Acts::AdaptiveGridDensityVertexFinder<trkGridSize, vfitter_t>::find(
         return maxZTRes.error();
       }
       z = (*maxZTRes).first;
+      t = (*maxZTRes).second;
     } else {
       // Get z value of highest density bin and width
       auto maxZTResAndWidth =
@@ -75,20 +79,22 @@ auto Acts::AdaptiveGridDensityVertexFinder<trkGridSize, vfitter_t>::find(
         return maxZTResAndWidth.error();
       }
       z = (*maxZTResAndWidth).first.first;
-      width = (*maxZTResAndWidth).second;
+      t = (*maxZTResAndWidth).first.second;
+      zWidth = (*maxZTResAndWidth).second;
     }
   }
 
-  // Construct output vertex
-  Vector3 seedPos = vertexingOptions.constraint.position() + Vector3(0., 0., z);
+  // Construct output vertex, t will be 0 if temporalTrkGridSize == 1
+  Vector4 seedPos =
+      vertexingOptions.constraint.fullPosition() + Vector4(0., 0., z, t);
 
   Vertex<InputTrack_t> returnVertex = Vertex<InputTrack_t>(seedPos);
 
   SquareMatrix4 seedCov = vertexingOptions.constraint.fullCovariance();
 
-  if (width != 0.) {
+  if (zWidth != 0.) {
     // Use z-constraint from seed width
-    seedCov(2, 2) = width * width;
+    seedCov(2, 2) = zWidth * zWidth;
   }
 
   returnVertex.setFullCovariance(seedCov);
@@ -98,9 +104,11 @@ auto Acts::AdaptiveGridDensityVertexFinder<trkGridSize, vfitter_t>::find(
   return seedVec;
 }
 
-template <int trkGridSize, typename vfitter_t>
-auto Acts::AdaptiveGridDensityVertexFinder<trkGridSize, vfitter_t>::
-    doesPassTrackSelection(const BoundTrackParameters& trk) const -> bool {
+template <int spatialTrkGridSize, int temporalTrkGridSize, typename vfitter_t>
+auto Acts::AdaptiveGridDensityVertexFinder<
+    spatialTrkGridSize, temporalTrkGridSize,
+    vfitter_t>::doesPassTrackSelection(const BoundTrackParameters& trk) const
+    -> bool {
   // Get required track parameters
   const double d0 = trk.parameters()[BoundIndices::eBoundLoc0];
   const double z0 = trk.parameters()[BoundIndices::eBoundLoc1];

Core/include/Acts/Vertexing/TrackDensityVertexFinder.ipp

@@ -22,18 +22,19 @@ auto Acts::TrackDensityVertexFinder<vfitter_t, track_density_t>::find(
 
   // Calculate seed position
   // Note: constraint position is (0,0,0) if no constraint provided
-  Vector3 seedPos = vertexingOptions.constraint.position() + Vector3(0., 0., z);
+  Vector4 seedPos =
+      vertexingOptions.constraint.fullPosition() + Vector4(0., 0., z, 0.);
 
   Vertex<InputTrack_t> returnVertex = Vertex<InputTrack_t>(seedPos);
 
-  SquareMatrix3 seedCov = vertexingOptions.constraint.covariance();
+  SquareMatrix4 seedCov = vertexingOptions.constraint.fullCovariance();
 
   // Check if a constraint is provided and set the new z position constraint
-  if (seedCov != SquareMatrix3::Zero() && std::isnormal(zAndWidth.second)) {
+  if (seedCov != SquareMatrix4::Zero() && std::isnormal(zAndWidth.second)) {
     seedCov(eZ, eZ) = zAndWidth.second * zAndWidth.second;
   }
 
-  returnVertex.setCovariance(seedCov);
+  returnVertex.setFullCovariance(seedCov);
 
   std::vector<Vertex<InputTrack_t>> seedVec{returnVertex};
 

Examples/Algorithms/Vertexing/src/AdaptiveMultiVertexFinderAlgorithm.cpp

@@ -61,7 +61,7 @@ ActsExamples::AdaptiveMultiVertexFinderAlgorithm::execute(
     Seeder seedFinder;
     return executeAfterSeederChoice<Seeder, Finder>(ctx, seedFinder);
   } else if (m_cfg.seedFinder == SeedFinder::AdaptiveGridSeeder) {
-    using Seeder = Acts::AdaptiveGridDensityVertexFinder<109, Fitter>;
+    using Seeder = Acts::AdaptiveGridDensityVertexFinder<109, 1, Fitter>;
     using Finder = Acts::AdaptiveMultiVertexFinder<Fitter, Seeder>;
     // The seeder config argument corresponds to the bin size in mm
     Seeder::Config seederConfig(0.05);