Template Function Acts::estimateTrackParamsFromSeed(spacepoint_iterator_t, spacepoint_iterator_t)¶
Defined in File EstimateTrackParamsFromSeed.hpp
Function Documentation¶
-
template<typename
spacepoint_iterator_t
>
std::optional<BoundVector>Acts
::
estimateTrackParamsFromSeed
(spacepoint_iterator_t spBegin, spacepoint_iterator_t spEnd)¶ Estimate the track parameters on the xy plane from at least three space points.
It assumes the trajectory projection on the xy plane is a circle, i.e. the magnetic field is along global z-axis.
The method is based on V. Karimaki NIM A305 (1991) 187-191: https://doi.org/10.1016/0168-9002(91)90533-V
no weights are used in Karimaki’s fit; d0 is the distance of the point of closest approach to the origin, 1/R is the curvature, phi is the angle of the direction propagation (counter clockwise as positive) at the point of cloest approach.
- Return
optional bound track parameters with the estimated d0, phi and 1/R stored with the indices, eBoundLoc0, eBoundPhi and eBoundQOverP, respectively. The bound parameters with other indices are set to zero.
- Template Parameters
spacepoint_iterator_t
: The type of space point iterator
- Parameters
spBegin
: is the begin iterator for the space pointsspEnd
: is the end iterator for the space points