Struct Acts::StraightLineStepper::State

struct State

State for track parameter propagation.

Public Functions

State() = delete
inline explicit State(const GeometryContext &gctx, const MagneticFieldContext &mctx, const BoundTrackParameters &par, double ssize = std::numeric_limits<double>::max(), double stolerance = s_onSurfaceTolerance)

Constructor from the initial bound track parameters.


the covariance matrix is copied when needed

  • gctx[in] is the context object for the geometry

  • mctx[in] is the context object for the magnetic field

  • par[in] The track parameters at start

  • ssize[in] is the maximum step size

  • stolerance[in] is the stepping tolerance

Public Members

Covariance cov = Covariance::Zero()
bool covTransport = false

Boolean to indicate if you need covariance transport.

FreeVector derivative = FreeVector::Zero()

The propagation derivative.

std::reference_wrapper<const GeometryContext> geoContext
Jacobian jacobian = Jacobian::Identity()

The full jacobian of the transport entire transport.

BoundToFreeMatrix jacToGlobal = BoundToFreeMatrix::Zero()

Jacobian from local to the global frame.

FreeMatrix jacTransport = FreeMatrix::Identity()

Pure transport jacobian part from runge kutta integration.

FreeVector pars = FreeVector::Zero()

Internal free vector parameters.

ParticleHypothesis particleHypothesis = ParticleHypothesis::pion()

Particle hypothesis.

double pathAccumulated = 0.

accummulated path length state

double previousStepSize = 0.
ConstrainedStep stepSize

adaptive step size of the runge-kutta integration

double tolerance = s_onSurfaceTolerance

The tolerance for the stepping.