Class AngularQuadrature

Defined in File angular_quadrature.h

Nested Relationships

Nested Types

Struct AngularQuadrature::HarmonicIndices

Inheritance Relationships

Derived Types

public opensn::LebedevQuadrature2DXY (Class LebedevQuadrature2DXY)
public opensn::LebedevQuadrature3DXYZ (Class LebedevQuadrature3DXYZ)
public opensn::ProductQuadrature (Class ProductQuadrature)
public opensn::SLDFEsqQuadrature (Class SLDFEsqQuadrature)
public opensn::TriangularQuadrature (Class TriangularQuadrature)

Class Documentation

class AngularQuadrature

Base class for angular quadratures used in discrete ordinates transport calculations.

Subclassed by opensn::LebedevQuadrature2DXY, opensn::LebedevQuadrature3DXYZ, opensn::ProductQuadrature, opensn::SLDFEsqQuadrature, opensn::TriangularQuadrature

Public Functions

inline virtual unsigned int GetQuadratureOrder() const: Quadrature-specific order parameter used by harmonic-selection rules.

inline virtual unsigned int GetNumPolarAngles() const: Number of polar angles used by harmonic-selection rules.

inline virtual unsigned int GetNumAzimuthalAngles() const: Number of azimuthal angles used by harmonic-selection rules.

virtual ~AngularQuadrature() = default

void BuildDiscreteToMomentOperator(): Compute the discrete-to-moment operator.

void BuildMomentToDiscreteOperator(): Compute the moment-to-discrete operator.

inline OperatorConstructionMethod GetOperatorConstructionMethod() const: Gets the current operator construction method.

NDArray<double, 2> const &GetDiscreteToMomentOperator() const

Return a reference to the precomputed discrete-to-moment operator.

The operator is accessed as (d,m), where d is the direction index and m is the moment index.

NDArray<double, 2> const &GetMomentToDiscreteOperator() const

Return a reference to the precomputed moment-to-discrete operator.

The operator is accessed as (d,m), where d is the direction index and m is the moment index.

const std::vector<HarmonicIndices> &GetMomentToHarmonicsIndexMap() const: Return a reference to the precomputed harmonic index map.

inline unsigned int GetDimension() const

inline unsigned int GetScatteringOrder() const

inline unsigned int GetNumMoments() const

inline size_t GetNumAngles() const

inline bool Empty() const

inline AngularQuadratureType GetType() const

virtual std::string GetName() const = 0: Return a user-facing quadrature name.

virtual double GetWeightSum() const: Return the sum of all quadrature weights.

inline const std::vector<QuadraturePointPhiTheta> &GetAbscissae() const

inline const QuadraturePointPhiTheta &GetAbscissa(size_t angle_index) const

inline const std::vector<double> &GetWeights() const

inline double GetWeight(size_t angle_index) const

inline const std::vector<Vector3> &GetOmegas() const

inline const Vector3 &GetOmega(size_t angle_index) const

std::vector<size_t> MapOppositeDirections() const

Map each direction index to the index of its opposite direction.

For 3D quadratures, the opposite of direction \(\Omega_n\) is \(-\Omega_n\). Lower dimensional quadratures store only a representative of each direction class, so the opposite direction is the one that is equivalent to \(-\Omega_n\): \((\Omega_x, \Omega_y, -\Omega_z)\) in 1D (the polar cosine changes sign) and \((-\Omega_x, -\Omega_y, \Omega_z)\) in 2D (quadratures hold only \(\Omega_z > 0\)).

Complexity is \(O(N^2)\) in the number of directions.

Throws:: std::logic_error – if an opposite direction is not in the quadrature set.

Protected Functions

inline explicit AngularQuadrature(AngularQuadratureType type, unsigned int dimension, unsigned int scattering_order, OperatorConstructionMethod method = OperatorConstructionMethod::STANDARD)

inline void SetOperatorConstructionMethod(OperatorConstructionMethod method): Sets the operator construction method.

void MakeHarmonicIndices(): Populate the map of moment index to spherical harmonic indices.

std::vector<HarmonicIndices> SelectGalerkinHarmonics(size_t num_angles) const

Harmonics that the selection rules give a Galerkin method for num_angles directions of this quadrature.

MakeHarmonicIndices uses it for the current directions.

void CheckMomentOperatorConsistency() const

Warns if the standard D2M and M2D operators are not inverse on the moment space.

Does nothing for Galerkin construction or until both operators are built for the current moments.

Protected Attributes

NDArray<double, 2> d2m_op_ = {}

Discrete-to-moment operator matrix.

OpenSn storage is indexed [angle][moment].

NDArray<double, 2> m2d_op_ = {}

Moment-to-discrete operator matrix.

OpenSn storage is indexed [angle][moment].

std::vector<HarmonicIndices> m_to_ell_em_map_ = {}: Mapping from moment index to spherical harmonic indices.

AngularQuadratureType type_: Quadrature type identifier.

unsigned int dimension_: Spatial dimension of the quadrature.

unsigned int scattering_order_: Maximum scattering order for moment calculations.

OperatorConstructionMethod construction_method_

std::vector<QuadraturePointPhiTheta> abscissae_ = {}: Quadrature point abscissae in spherical coordinates.

std::vector<double> weights_ = {}: Quadrature weights.

std::vector<Vector3> omegas_ = {}: Quadrature point direction vectors in Cartesian coordinates.

struct HarmonicIndices

Spherical harmonic indices for moment-to-direction mappings.

Public Functions

HarmonicIndices() = default

inline HarmonicIndices(unsigned int ell, int m)

inline bool operator==(const HarmonicIndices &other) const

Public Members

unsigned int ell = 0: Degree of the spherical harmonic.

int m = 0: Order of the spherical harmonic.