Struct ActsFatras::FreeParametersSmearer

template<typename generator_t, size_t kSize>
struct ActsFatras::FreeParametersSmearer

Uncorrelated smearing algorithm for fast digitisation of free parameters.

The smearer takes a single simulated Hit and generates a smeared parameter vector and associated covariance matrix.

tparam generator_t

Random number generator type

tparam kSize

Number of smeared parameters

Note

Uncorrelated smearing of the direction using each components individually is not recommended

Public Types

using CovarianceMatrix = Acts::ActsSymMatrix<kSize>

using ParametersVector = Acts::ActsVector<kSize>

using Result = Acts::Result<std::pair<ParametersVector, CovarianceMatrix>>

using Scalar = Acts::ActsScalar

Public Functions

inline Result operator()(generator_t &rng, const Hit &hit) const

Generate smeared measured for configured parameters.

Parameters

• rng – Random number generator

• hit – Simulated hit

Returns

Smeared free parameter set wrapped in a Result<…> object

Returns

• Smeared – parameters vector and associated covariance on success

• Error – code for failure

Public Members

std::array<Acts::FreeIndices, kSize> indices

Parameter indices that will be used to create the smeared measurements.

std::array<SingleParameterSmearFunction<generator_t>, kSize> smearFunctions

Public Static Functions

static inline constexpr size_t size()