Propagation

Detailed Description

Particle propagation.

The transport Jacobian used for covariance transport is not written by hand: it is derived symbolically with sympy and printed as C++ at build time. See Transport Jacobian code generation for the derivation, the sparsity patterns it exploits and the code it produces.

Steppers

GenericRungeKuttaStepper

Acts::GenericRungeKuttaStepper is a reference stepper, similar to what Acts::Experimental::TryAllNavigator is for navigation. It is not optimised for speed. It integrates the equation of motion with any explicit Runge-Kutta tableau and an exact transport jacobian, so other steppers can be validated against it.

Topics
	Magnetic Field
	A description of magnetic field configurations for algorithms.
	Symbolic code generation
	How the Acts::SympyStepper kernels are derived with sympy, and the ATLAS-form arrangement they use.