ConstraintMap

Read-only expansion map for value and identification constraints.

Defined in Rodin/Assembly/ConstraintMap.h

template <
  class Scalar>
class ConstraintMap;

Identification constraints are stored as rows of the expansion map . For unconstrained DOFs, expand() returns the identity row { { i, 1 } }.

The map supports canonicalization of identification constraints:

duplicate masters are merged;
zero coefficients are pruned;
self-references are removed algebraically;
identity constraints are ignored;
constraints such as , , are converted to fixed constraints;
transitive identifications are flattened by finalize.

After calling finalize, this object can be shared by OpenMP assembly loops as a read-only expansion map.

Public types

struct Entry: One master DOF contribution in an expansion row.
using Expansion = std::vector<Entry>: Expansion row for a constrained DOF.

Constructors, destructors, conversion operators

ConstraintMap(size_t size) explicit: Constructs an identity constraint map.

Public functions

void reset(size_t size): Resets the map to the identity expansion on size DOFs.
auto size() const -> size_t: Gets the number of DOFs represented by the map.
auto isFixed(Index i) const -> bool: Tests whether a DOF is fixed to a value.
auto isIdentified(Index i) const -> bool: Tests whether a DOF is identified with master DOFs.
auto getFixedValue(Index i) const -> Scalar: Gets the prescribed value for a fixed DOF.
auto expand(Index i) const -> const Expansion&: Expands a DOF into its master DOF row.
auto getIdentifiedRows() const -> const std::vector<Index>&: Gets the indices of rows carrying identification constraints.
auto getIdentificationValue(Index i) const -> Scalar: Gets the affine defect value for an identified DOF.
void setFixed(Index i, Scalar value): Marks a DOF as fixed to a prescribed value.
template<class Entries> void setIdentification(Index slave, const Entries& entries): Sets a homogeneous identification row.
template<class Entries> void setIdentification(Index slave, const Entries& entries, Scalar value): Sets an affine identification row.
void finalize(): Flattens transitive identification constraints.

Function documentation

ConstraintMap(size_t size) explicit

Constructs an identity constraint map.

Parameters
size	Number of DOFs represented by the map.

void reset(size_t size)

Resets the map to the identity expansion on size DOFs.

Parameters
size	Number of DOFs represented by the map.

size_t size() const

Gets the number of DOFs represented by the map.

Returns	Number of expansion rows.

bool isFixed(Index i) const

Tests whether a DOF is fixed to a value.

Parameters
i	DOF index.
Returns	Whether the degree of freedom has a prescribed value.

bool isIdentified(Index i) const

Tests whether a DOF is identified with master DOFs.

Parameters
i	DOF index.
Returns	Whether the degree of freedom is identified with master degrees of freedom.

Scalar getFixedValue(Index i) const

Gets the prescribed value for a fixed DOF.

Parameters
i	Fixed DOF index.
Returns	Prescribed scalar value.

const Expansion& expand(Index i) const

Expands a DOF into its master DOF row.

Parameters
i	DOF index.
Returns	Expansion row for `i`.

const std::vector<Index>& getIdentifiedRows() const

Gets the indices of rows carrying identification constraints.

Returns	Identified slave DOF indices.

Scalar getIdentificationValue(Index i) const

Gets the affine defect value for an identified DOF.

Parameters
i	Identified slave DOF index.
Returns	Constant term in the identification row.

void setFixed(Index i, Scalar value)

Marks a DOF as fixed to a prescribed value.

Parameters
i	DOF index.
value	Prescribed scalar value.

template<class Scalar> template<class Entries>
void setIdentification(Index slave, const Entries& entries)

Sets a homogeneous identification row.

Parameters
slave	Slave DOF index.
entries	Master expansion entries.

template<class Scalar> template<class Entries>
void setIdentification(Index slave, const Entries& entries, Scalar value)

Sets an affine identification row.

Parameters
slave	Slave DOF index.
entries	Master expansion entries.
value	Constant term in the identification.

void finalize()

Flattens transitive identification constraints.

Example:

becomes:

Cycles such as , are rejected.