Class DynamicMatrix¶

Class Documentation¶

class DynamicMatrix¶

The DynamicMatrix class represents a matrix that is optimized for sparse matrices and internally uses a graph data structure. DynamicMatrix should be used when changes to the structure of the matrix are frequent.

Public Functions

DynamicMatrix()¶

Default constructor

DynamicMatrix(count dimension, double zero = 0.0)¶

Constructs the Matrix with size dimension x dimension.

Parameters:

• dimension – Defines how many rows and columns this matrix has.

• zero – The zero element (default is 0.0).

DynamicMatrix(count nRows, count nCols, double zero = 0.0)¶

Constructs the Matrix with size nRows x nCols.

Parameters:

• nRows – Number of rows.

• nCols – Number of columns.

• zero – The zero element (default is 0.0).

DynamicMatrix(count dimension, const std::vector<Triplet> &triplets, double zero = 0.0)¶

Constructs the dimension x dimension Matrix from the elements at position positions with values @values.

Parameters:

• dimension – Defines how many rows and columns this matrix has.

• triplets – The nonzero elements.

• zero – The zero element (default is 0.0).

DynamicMatrix(count nRows, count nCols, const std::vector<Triplet> &triplets, double zero = 0.0)¶

Constructs the nRows x nCols Matrix from the elements at position positions with values @values.

Parameters:

• nRows – Defines how many rows this matrix has.

• nCols – Defines how many columns this matrix has.

• triplets – The nonzero elements.

• zero – The zero element (default is 0.0).

inline bool operator==(const DynamicMatrix &other) const¶

Compares this matrix to other and returns true if the shape and zero element are the same as well as all entries, otherwise returns false.

Parameters:

other –

inline bool operator!=(const DynamicMatrix &other) const¶

Compares this matrix to other and returns false if the shape and zero element are the same as well as all entries, otherwise returns true.

Parameters:

other –

inline count numberOfRows() const¶

Returns:

Number of rows.

inline count numberOfColumns() const¶

Returns:

Number of columns.

inline double getZero() const¶

Returns the zero element of the matrix.

count nnzInRow(index i) const¶

Parameters:

i – The row index.

Returns:

Number of non-zeros in row i.

count nnz() const¶

Returns:

Number of non-zeros in this matrix.

double operator()(index i, index j) const¶

Returns:

Value at matrix position (i,j).

void setValue(index i, index j, double value)¶

Set the matrix at position (i, j) to value.

Vector row(index i) const¶

Returns:

Row i of this matrix as vector.

Vector column(index j) const¶

Returns:

Column j of this matrix as vector.

Vector diagonal() const¶

Returns:

The main diagonal of this matrix.

DynamicMatrix operator+(const DynamicMatrix &other) const¶

Adds this matrix to other and returns the result.

Returns:

The sum of this matrix and other.

DynamicMatrix &operator+=(const DynamicMatrix &other)¶

Adds other to this matrix.

Returns:

Reference to this matrix.

DynamicMatrix operator-(const DynamicMatrix &other) const¶

Subtracts other from this matrix and returns the result.

Returns:

The difference of this matrix and other.

DynamicMatrix &operator-=(const DynamicMatrix &other)¶

Subtracts other from this matrix.

Returns:

Reference to this matrix.

DynamicMatrix operator*(double scalar) const¶

Multiplies this matrix with a scalar specified in scalar and returns the result.

Returns:

The result of multiplying this matrix with scalar.

DynamicMatrix &operator*=(double scalar)¶

Multiplies this matrix with a scalar specified in scalar.

Returns:

Reference to this matrix.

Vector operator*(const Vector &vector) const¶

Multiplies this matrix with vector and returns the result.

Returns:

The result of multiplying this matrix with vector.

DynamicMatrix operator*(const DynamicMatrix &other) const¶

Multiplies this matrix with other and returns the result in a new matrix.

Returns:

The result of multiplying this matrix with other.

DynamicMatrix operator/(double divisor) const¶

Divides this matrix by a divisor specified in divisor and returns the result in a new matrix.

Returns:

The result of dividing this matrix by divisor.

DynamicMatrix &operator/=(double divisor)¶

Divides this matrix by a divisor specified in divisor.

Returns:

Reference to this matrix.

DynamicMatrix transpose() const¶

Transposes this matrix and returns it.

DynamicMatrix extract(const std::vector<index> &rowIndices, const std::vector<index> &columnIndices) const¶

Extracts a matrix with rows and columns specified by rowIndices and columnIndices from this matrix. The order of rows and columns is equal to the order in rowIndices and columnIndices. It is also possible to specify a row or column more than once to get duplicates.

Parameters:

• rowIndices –

• columnIndices –

void assign(const std::vector<index> &rowIndices, const std::vector<index> &columnIndices, const DynamicMatrix &source)¶

Assign the contents of the matrix source to this matrix at rows and columns specified by rowIndices and columnIndices. That is, entry (i,j) of source is assigned to entry (rowIndices[i], columnIndices[j]) of this matrix. Note that the dimensions of @rowIndices and columnIndices must coincide with the number of rows and columns of source.

Parameters:

• rowIndices –

• columnIndices –

• source –

template<typename F>
void apply(F unaryElementFunction)¶

Applies the unary function unaryElementFunction to each value in the matrix. Note that it must hold that the function applied to the zero element of this matrix returns the zero element.

Parameters:

unaryElementFunction –

template<typename L>
inline void forNonZeroElementsInRow(index row, L handle) const¶

Iterate over all non-zero elements of row row in the matrix and call handle(index row, index column, double value)

template<typename L>
inline void parallelForNonZeroElementsInRow(index i, L handle) const¶

Iterate in parallel over all non-zero elements of row row in the matrix and call handler(index column, double value)

template<typename L>
inline void forElementsInRow(index i, L handle) const¶

Iterate over all elements in row i in the matrix and call handle(index column, double value)

template<typename L>
inline void parallelForElementsInRow(index row, L handle) const¶

Iterate in parallel over all elements (including zeros) of row row in the matrix and call handler(index column, double value)

template<typename L>
inline void forElementsInRowOrder(L handle) const¶

Iterate over all elements (including zeros) of the matrix in row order and call handler (lambda closure).

template<typename L>
inline void parallelForElementsInRowOrder(L handle) const¶

Iterate in parallel over all elements (including zeros) in row order and call handle (lambda closure) on elements of the matrix.

template<typename L>
inline void forNonZeroElementsInRowOrder(L handle) const¶

Iterate over all non-zero elements of the matrix in row order and call handle(index row, index column, double value).

template<typename L>
inline void parallelForNonZeroElementsInRowOrder(L handle) const¶

Iterate in parallel over all rows and call handle(index row, index column, double value) on non-zero elements of the matrix.

Public Static Functions

static DynamicMatrix mTmMultiply(const DynamicMatrix &A, const DynamicMatrix &B)¶

Computes A^T * B.

Parameters:

• A –

• B –

static DynamicMatrix mmTMultiply(const DynamicMatrix &A, const DynamicMatrix &B)¶

Computes A * B^T.

Parameters:

• A –

• B –

static Vector mTvMultiply(const DynamicMatrix &matrix, const Vector &vector)¶

Computes matrix^T * vector

Parameters:

• matrix –

• vector –

static DynamicMatrix adjacencyMatrix(const Graph &graph, double zero = 0.0)¶

Returns the (weighted) adjacency matrix of the (weighted) Graph graph.

Parameters:

graph –

static DynamicMatrix diagonalMatrix(const Vector &diagonalElements, double zero = 0.0)¶

Creates a diagonal matrix with dimension equal to the dimension of the Vector diagonalElements. The values on the diagonal are the ones stored in diagonalElements (i.e. D(i,i) = diagonalElements[i]).

Parameters:

diagonalElements –

static DynamicMatrix incidenceMatrix(const Graph &graph, double zero = 0.0)¶

Returns the (weighted) incidence matrix of the (weighted) Graph graph.

Parameters:

graph –

static DynamicMatrix laplacianMatrix(const Graph &graph, double zero = 0.0)¶

Returns the (weighted) Laplacian matrix of the (weighteD) Graph graph.

Parameters:

graph –

static DynamicMatrix normalizedLaplacianMatrix(const Graph &graph, double zero = 0.0)¶

Returns the (weighted) normalized Laplacian matrix of the (weighted) Graph graph

Parameters:

graph –

Protected Attributes

Graph graph¶

count nRows¶

count nCols¶

double zero¶