Tests/IntegrationTests/PropagationCompareGenericRungeKuttaHelixConstant.cpp

0001 // This file is part of the ACTS project.
0002 //
0003 // Copyright (C) 2016 CERN for the benefit of the ACTS project
0004 //
0005 // This Source Code Form is subject to the terms of the Mozilla Public
0006 // License, v. 2.0. If a copy of the MPL was not distributed with this
0007 // file, You can obtain one at https://mozilla.org/MPL/2.0/.
0008
0009 #include <boost/test/data/test_case.hpp>
0010 #include <boost/test/unit_test.hpp>
0011
0012 #include "Acts/Geometry/GeometryContext.hpp"
0013 #include "Acts/MagneticField/ConstantBField.hpp"
0014 #include "Acts/MagneticField/MagneticFieldContext.hpp"
0015 #include "Acts/Propagator/GenericRungeKuttaStepper.hpp"
0016 #include "Acts/Propagator/HelixStepper.hpp"
0017 #include "Acts/Propagator/Propagator.hpp"
0018
0019 #include <utility>
0020
0021 #include "PropagationDatasets.hpp"
0022 #include "PropagationTests.hpp"
0023
0024 namespace {
0025
0026 namespace ds = ActsTests::PropagationDatasets;
0027
0028 using namespace Acts;
0029 using namespace UnitLiterals;
0030
0031 using MagneticField = ConstantBField;
0032 using GenericRungeKuttaPropagator = Propagator<GenericRungeKuttaStepper>;
0033 using HelixPropagator = Propagator<HelixStepper>;
0034
0035 // The helix is exact in a constant field, so it is the reference here.
0036 constexpr auto epsPos = 1_um;
0037 constexpr auto epsTime = 1_um;
0038 constexpr auto epsDir = 0.125_mrad;
0039 constexpr auto epsMom = 1_eV;
0040 constexpr auto epsCov = 0.025;
0041
0042 // A step to the straight-line distance of a surface passes a surface
0043 // perpendicular to the track by about |(q/p) T x B|^2 h^3 / 3, which is up to
0044 // about 2 mm for these datasets. The next step goes back, so accept
0045 // intersections that far behind the track. Only for planes and discs: they
0046 // have one intersection, while the target cylinder can have its second
0047 // intersection within 1 cm behind the track.
0048 struct TargetReached : public SurfaceReached {
0049   TargetReached() : SurfaceReached(-1_cm) {}
0050 };
0051
0052 const auto geoCtx = GeometryContext::dangerouslyDefaultConstruct();
0053 const MagneticFieldContext magCtx;
0054
0055 inline std::pair<GenericRungeKuttaPropagator, HelixPropagator> makePropagators(
0056     double bz) {
0057   auto field = std::make_shared<MagneticField>(Vector3(0.0, 0.0, bz));
0058   return {GenericRungeKuttaPropagator(GenericRungeKuttaStepper(field)),
0059           HelixPropagator(HelixStepper(field))};
0060 }
0061
0062 }  // namespace
0063
0064 BOOST_AUTO_TEST_SUITE(PropagationCompareGenericRungeKuttaHelixConstant)
0065
0066 BOOST_DATA_TEST_CASE(Forward,
0067                      ds::phi* ds::thetaWithoutBeam* ds::absMomentum*
0068                          ds::chargeNonZero* ds::pathLength* ds::magneticField,
0069                      phi, theta, p, q, s, bz) {
0070   auto [genericRungeKuttaPropagator, helixPropagator] = makePropagators(bz);
0071   runForwardComparisonTest(
0072       genericRungeKuttaPropagator, helixPropagator, geoCtx, magCtx,
0073       makeParametersCurvilinearWithCovariance(phi, theta, p, q), s, epsPos,
0074       epsTime, epsDir, epsMom, epsCov);
0075 }
0076
0077 BOOST_DATA_TEST_CASE(ToCylinderAlongZ,
0078                      ds::phi* ds::thetaWithoutBeam* ds::absMomentum*
0079                          ds::chargeNonZero* ds::pathLength* ds::magneticField,
0080                      phi, theta, p, q, s, bz) {
0081   auto [genericRungeKuttaPropagator, helixPropagator] = makePropagators(bz);
0082   runToSurfaceComparisonTest(
0083       genericRungeKuttaPropagator, helixPropagator, geoCtx, magCtx,
0084       makeParametersCurvilinearWithCovariance(phi, theta, p, q), s,
0085       ZCylinderSurfaceBuilder(), epsPos, epsTime, epsDir, epsMom, epsCov);
0086 }
0087
0088 BOOST_DATA_TEST_CASE(
0089     ToDisc,
0090     ds::phiWithoutAmbiguity* ds::thetaWithoutBeam* ds::absMomentum*
0091         ds::chargeNonZero* ds::pathLength* ds::magneticField,
0092     phi, theta, p, q, s, bz) {
0093   auto [genericRungeKuttaPropagator, helixPropagator] = makePropagators(bz);
0094   runToSurfaceComparisonTest(
0095       genericRungeKuttaPropagator, helixPropagator, geoCtx, magCtx,
0096       makeParametersCurvilinearWithCovariance(phi, theta, p, q), s,
0097       DiscSurfaceBuilder(), epsPos, epsTime, epsDir, epsMom, epsCov,
0098       TargetReached());
0099 }
0100
0101 BOOST_DATA_TEST_CASE(ToPlane,
0102                      ds::phi* ds::thetaWithoutBeam* ds::absMomentum*
0103                          ds::chargeNonZero* ds::pathLength* ds::magneticField,
0104                      phi, theta, p, q, s, bz) {
0105   auto [genericRungeKuttaPropagator, helixPropagator] = makePropagators(bz);
0106   runToSurfaceComparisonTest(
0107       genericRungeKuttaPropagator, helixPropagator, geoCtx, magCtx,
0108       makeParametersCurvilinearWithCovariance(phi, theta, p, q), s,
0109       PlaneSurfaceBuilder(), epsPos, epsTime, epsDir, epsMom, epsCov,
0110       TargetReached());
0111 }
0112
0113 BOOST_DATA_TEST_CASE(ToStrawAlongZ,
0114                      ds::phi* ds::thetaWithoutBeam* ds::absMomentum*
0115                          ds::chargeNonZero* ds::pathLength* ds::magneticField,
0116                      phi, theta, p, q, s, bz) {
0117   auto [genericRungeKuttaPropagator, helixPropagator] = makePropagators(bz);
0118   runToSurfaceComparisonTest(
0119       genericRungeKuttaPropagator, helixPropagator, geoCtx, magCtx,
0120       makeParametersCurvilinearWithCovariance(phi, theta, p, q), s,
0121       ZStrawSurfaceBuilder(), epsPos, epsTime, epsDir, epsMom, epsCov);
0122 }
0123
0124 BOOST_AUTO_TEST_SUITE_END()