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#include "TrackingTools/PatternTools/interface/TSCPBuilderNoMaterial.h"
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#include "DataFormats/GeometrySurface/interface/Surface.h"
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#include "TrackingTools/TrajectoryState/interface/FreeTrajectoryState.h"
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#include "TrackingTools/AnalyticalJacobians/interface/AnalyticalCurvilinearJacobian.h"
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#include "DataFormats/GeometrySurface/interface/BoundPlane.h"
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#include "TrackingTools/GeomPropagators/interface/HelixBarrelPlaneCrossingByCircle.h"
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#include "TrackingTools/TrajectoryParametrization/interface/TrajectoryStateExceptions.h"
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#include "MagneticField/Engine/interface/MagneticField.h"
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#include "FWCore/MessageLogger/interface/MessageLogger.h"
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TrajectoryStateClosestToPoint
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TSCPBuilderNoMaterial::operator() (const FTS& originalFTS,
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const GlobalPoint& referencePoint) const
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{
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if (positionEqual(referencePoint, originalFTS.position()))
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return constructTSCP(originalFTS, referencePoint);
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// Now do the propagation or whatever...
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PairBoolFTS newStatePair =
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createFTSatTransverseImpactPoint(originalFTS, referencePoint);
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if (newStatePair.first) {
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return constructTSCP(newStatePair.second, referencePoint);
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} else {
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return TrajectoryStateClosestToPoint();
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}
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}
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TrajectoryStateClosestToPoint
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TSCPBuilderNoMaterial::operator() (const TSOS& originalTSOS,
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const GlobalPoint& referencePoint) const
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{
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if (positionEqual(referencePoint, originalTSOS.globalPosition()))
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return constructTSCP(*originalTSOS.freeState(), referencePoint);
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// Now do the propagation
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PairBoolFTS newStatePair =
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createFTSatTransverseImpactPoint(*originalTSOS.freeState(), referencePoint);
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if (newStatePair.first) {
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return constructTSCP(newStatePair.second, referencePoint);
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} else {
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return TrajectoryStateClosestToPoint();
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}
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}
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TSCPBuilderNoMaterial::PairBoolFTS
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TSCPBuilderNoMaterial::createFTSatTransverseImpactPoint(
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const FTS& originalFTS, const GlobalPoint& referencePoint) const
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{
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//
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// Straight line approximation? |rho|<1.e-10 equivalent to ~ 1um
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// difference in transversal position at 10m.
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//
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if( fabs(originalFTS.transverseCurvature())<1.e-10 ) {
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return createFTSatTransverseImpactPointNeutral(originalFTS, referencePoint);
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} else {
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return createFTSatTransverseImpactPointCharged(originalFTS, referencePoint);
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}
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}
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TSCPBuilderNoMaterial::PairBoolFTS
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TSCPBuilderNoMaterial::createFTSatTransverseImpactPointCharged(
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const FTS& originalFTS, const GlobalPoint& referencePoint) const
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{
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GlobalVector pvecOrig = originalFTS.momentum();
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GlobalPoint xvecOrig = originalFTS.position();
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double kappa = originalFTS.transverseCurvature();
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double pxOrig = pvecOrig.x();
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double pyOrig = pvecOrig.y();
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double pzOrig = pvecOrig.z();
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double xOrig = xvecOrig.x();
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double yOrig = xvecOrig.y();
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double zOrig = xvecOrig.z();
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// double fac = 1./originalFTS.charge()/MagneticField::inInverseGeV(referencePoint).z();
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double fac = 1./originalFTS.charge()/
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(originalFTS.parameters().magneticField().inInverseGeV(referencePoint).z());
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GlobalVectorDouble xOrig2Centre = GlobalVectorDouble(fac * pyOrig, -fac * pxOrig, 0.);
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GlobalVectorDouble xOrigProj = GlobalVectorDouble(xOrig, yOrig, 0.);
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GlobalVectorDouble xRefProj = GlobalVectorDouble(referencePoint.x(), referencePoint.y(), 0.);
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GlobalVectorDouble deltax = xRefProj-xOrigProj-xOrig2Centre;
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GlobalVectorDouble ndeltax = deltax.unit();
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PropagationDirection direction = anyDirection;
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Surface::PositionType pos(referencePoint);
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// Need to define plane with orientation as the
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// ImpactPointSurface
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GlobalVector X(ndeltax.x(), ndeltax.y(), ndeltax.z());
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GlobalVector Y(0.,0.,1.);
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Surface::RotationType rot(X,Y);
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BoundPlane* plane = new BoundPlane(pos,rot);
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// Using Teddy's HelixBarrelPlaneCrossingByCircle for general barrel planes.
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// A large variety of other,
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// direct solutions turned out to be not so stable numerically.
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HelixBarrelPlaneCrossingByCircle
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planeCrossing(HelixPlaneCrossing::PositionType(xOrig, yOrig, zOrig),
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HelixPlaneCrossing::DirectionType(pxOrig, pyOrig, pzOrig),
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kappa, direction);
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std::pair<bool,double> propResult = planeCrossing.pathLength(*plane);
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if ( !propResult.first ) {
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edm::LogWarning ("TSCPBuilderNoMaterial") << "Propagation to perigee plane failed!";
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return PairBoolFTS(false, FreeTrajectoryState() );
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}
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double s = propResult.second;
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HelixPlaneCrossing::PositionType xGen = planeCrossing.position(s);
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GlobalPoint xPerigee = GlobalPoint(xGen.x(),xGen.y(),xGen.z());
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// direction (reconverted to GlobalVector, renormalised)
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HelixPlaneCrossing::DirectionType pGen = planeCrossing.direction(s);
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pGen *= pvecOrig.mag()/pGen.mag();
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GlobalVector pPerigee = GlobalVector(pGen.x(),pGen.y(),pGen.z());
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delete plane;
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if (originalFTS.hasError()) {
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const AlgebraicSymMatrix55 &errorMatrix = originalFTS.curvilinearError().matrix();
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AnalyticalCurvilinearJacobian curvilinJacobian(originalFTS.parameters(), xPerigee,
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pPerigee, s);
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const AlgebraicMatrix55 &jacobian = curvilinJacobian.jacobian();
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CurvilinearTrajectoryError cte( ROOT::Math::Similarity(jacobian, errorMatrix) );
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return PairBoolFTS(true,
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FreeTrajectoryState(GlobalTrajectoryParameters(xPerigee, pPerigee, originalFTS.charge(),
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&(originalFTS.parameters().magneticField())), cte) );
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}
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else {
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return PairBoolFTS(true,
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FreeTrajectoryState(GlobalTrajectoryParameters(xPerigee, pPerigee, originalFTS.charge(),
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&(originalFTS.parameters().magneticField()))) );
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}
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}
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TSCPBuilderNoMaterial::PairBoolFTS
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TSCPBuilderNoMaterial::createFTSatTransverseImpactPointNeutral(const FTS& originalFTS,
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const GlobalPoint& referencePoint) const
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{
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GlobalPoint xvecOrig = originalFTS.position();
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double phi = originalFTS.momentum().phi();
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double theta = originalFTS.momentum().theta();
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double xOrig = xvecOrig.x();
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double yOrig = xvecOrig.y();
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double zOrig = xvecOrig.z();
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double xR = referencePoint.x();
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double yR = referencePoint.y();
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double s2D = (xR - xOrig) * cos(phi) + (yR - yOrig) * sin(phi);
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double s = s2D / sin(theta);
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double xGen = xOrig + s2D*cos(phi);
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double yGen = yOrig + s2D*sin(phi);
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double zGen = zOrig + s2D/tan(theta);
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GlobalPoint xPerigee = GlobalPoint(xGen, yGen, zGen);
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GlobalVector pPerigee = originalFTS.momentum();
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if (originalFTS.hasError()) {
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const AlgebraicSymMatrix55 &errorMatrix = originalFTS.curvilinearError().matrix();
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AnalyticalCurvilinearJacobian curvilinJacobian(originalFTS.parameters(), xPerigee,
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pPerigee, s);
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const AlgebraicMatrix55 &jacobian = curvilinJacobian.jacobian();
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CurvilinearTrajectoryError cte( ROOT::Math::Similarity(jacobian, errorMatrix) );
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return PairBoolFTS(true,
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FreeTrajectoryState(GlobalTrajectoryParameters(xPerigee, pPerigee, originalFTS.charge(),
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&(originalFTS.parameters().magneticField())), cte));
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}
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else {
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return PairBoolFTS(true,
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FreeTrajectoryState(GlobalTrajectoryParameters(xPerigee, pPerigee, originalFTS.charge(),
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&(originalFTS.parameters().magneticField()))) );
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}
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}
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