A matrix type. More...

#include <geogram/basic/matrix.h>

Public Types
typedef Matrix< DIM, FT >	matrix_type

typedef FT	value_type

Public Member Functions
	Matrix ()
	Default constructor.

	Matrix (const FT *vals)
	Constructs a matrix from an array of values.

	Matrix (const std::initializer_list< std::initializer_list< FT > > &Mi)
	Constructs a matrix from 2d array of initializers.

index_t	dimension () const
	Gets the matrix dimension.

void	load_zero ()
	Clears the matrix.

void	load_identity ()
	Sets the matrix to identity.

bool	is_identity () const
	Tests whether a matrix is the identity matrix.

FT &	operator() (index_t i, index_t j)
	Gets a modifiable element.

const FT &	operator() (index_t i, index_t j) const
	Gets a non-modifiable element.

matrix_type &	operator+= (const matrix_type &m)
	Adds a matrix in place.

matrix_type &	operator-= (const matrix_type &m)
	Subtracts a matrix in place.

matrix_type &	operator*= (FT val)
	Multiplies by a scalar in place.

matrix_type &	operator/= (FT val)
	Divides by a scalar in place.

matrix_type	operator+ (const matrix_type &m) const
	Adds 2 matrices.

matrix_type	operator- (const matrix_type &m) const
	Subtracts 2 matrices.

matrix_type	operator* (FT val) const
	Multiplies a matrix by a scalar.

matrix_type	operator/ (FT val) const
	Divides a matrix by a scalar.

matrix_type	operator* (const matrix_type &m) const
	Multiplies 2 matrices.

matrix_type	inverse () const
	Computes the inverse matrix.

bool	compute_inverse (matrix_type &result) const
	Computes the inverse matrix.

matrix_type	transpose () const
	Computes the transposed matrix.

const FT *	data () const
	Gets non-modifiable matrix data.

FT *	data ()
	Gets modifiable matrix data.

void	get_lower_triangle (FT *store) const
	Gets the lower triangle of the matrix.

Static Public Attributes
static constexpr index_t	dim = DIM

Related Symbols
(Note that these are not member symbols.)
template<index_t DIM, class FT >
std::ostream &	operator<< (std::ostream &output, const Matrix< DIM, FT > &m)
	Writes a matrix to a stream.

template<index_t DIM, class FT >
std::istream &	operator>> (std::istream &input, Matrix< DIM, FT > &m)
	Reads a matrix from a stream.

template<index_t DIM, class FT >
void	mult (const Matrix< DIM, FT > &M, const FT x, FT y)
	Multiplies a matrix by a vector.

Detailed Description

template<index_t DIM, class FT>
class GEO::Matrix< DIM, FT >

A matrix type.

Matrix implements a square matrix of dimension DIM. containing coefficients of type T. Type T is expected to be a numeric type. Matrix provides the classical matrix operations.

Template Parameters

FT	type of the matrix elements
DIM	dimension of the matrix

Definition at line 66 of file matrix.h.

Member Typedef Documentation

◆ matrix_type

template<index_t DIM, class FT >

typedef Matrix<DIM, FT> GEO::Matrix< DIM, FT >::matrix_type

This matrix type

Definition at line 69 of file matrix.h.

◆ value_type

template<index_t DIM, class FT >

typedef FT GEO::Matrix< DIM, FT >::value_type

The type of the values

Definition at line 72 of file matrix.h.

Constructor & Destructor Documentation

◆ Matrix() [1/3]

template<index_t DIM, class FT >

GEO::Matrix< DIM, FT >::Matrix ( )

inline

Default constructor.

This initializes the matrix to the identity matrix

See also: load_identity()

Definition at line 82 of file matrix.h.

◆ Matrix() [2/3]

template<index_t DIM, class FT >

GEO::Matrix< DIM, FT >::Matrix ( const FT * vals )

inlineexplicit

Constructs a matrix from an array of values.

Parameters

[in] vals a const pointer to the DIM*DIM values, coefficients of the same rows are consecutive in memory, i is the slowly varying index and j the quickly varying one.

Definition at line 92 of file matrix.h.

◆ Matrix() [3/3]

template<index_t DIM, class FT >

GEO::Matrix< DIM, FT >::Matrix ( const std::initializer_list< std::initializer_list< FT > > & Mi )

inline

Constructs a matrix from 2d array of initializers.

Parameters

[in] Mi a 2d array of values to be copied to the matrix.

Definition at line 105 of file matrix.h.

Member Function Documentation

◆ compute_inverse()

template<index_t DIM, class FT >

bool GEO::Matrix< DIM, FT >::compute_inverse ( matrix_type & result ) const

inline

Computes the inverse matrix.

Computes matrix M such that (this * M) = identity

Parameters

[out] result the inverse matrix

Returns: true if the matrix is inversible

Return values

false otherwise

Definition at line 350 of file matrix.h.

◆ data() [1/2]

template<index_t DIM, class FT >

FT * GEO::Matrix< DIM, FT >::data ( )

inline

Gets modifiable matrix data.

For interfacing with Fortran, OpenGL etc...

Returns: a pointer to the first element of the matrix

Definition at line 431 of file matrix.h.

◆ data() [2/2]

template<index_t DIM, class FT >

const FT * GEO::Matrix< DIM, FT >::data ( ) const

inline

Gets non-modifiable matrix data.

For interfacing with Fortran, OpenGL etc...

Returns: a const pointer to the first element of the matrix

Definition at line 421 of file matrix.h.

◆ dimension()

template<index_t DIM, class FT >

index_t GEO::Matrix< DIM, FT >::dimension ( ) const

inline

Gets the matrix dimension.

Returns: the value of DIM

Definition at line 124 of file matrix.h.

◆ get_lower_triangle()

template<index_t DIM, class FT >

void GEO::Matrix< DIM, FT >::get_lower_triangle ( FT * store ) const

inline

Gets the lower triangle of the matrix.

Gets all the coefficients of the matrix under the diagonal (included) to array store, Array store must be large enough to contain (DIM * (DIM+1))/2 values.

Parameters

[in] store an array of at least (DIM * (DIM+1))/2 values

Definition at line 442 of file matrix.h.

◆ inverse()

template<index_t DIM, class FT >

matrix_type GEO::Matrix< DIM, FT >::inverse ( ) const

inline

Computes the inverse matrix.

Computes matrix M such that (this * M) = identity

Returns: the inverse matrix

Definition at line 335 of file matrix.h.

◆ is_identity()

template<index_t DIM, class FT >

bool GEO::Matrix< DIM, FT >::is_identity ( ) const

inline

Tests whether a matrix is the identity matrix.

Return values

true	if the matrix is the identity matrix
false	otherwise

Definition at line 158 of file matrix.h.

◆ load_identity()

template<index_t DIM, class FT >

void GEO::Matrix< DIM, FT >::load_identity ( )

inline

Sets the matrix to identity.

This sets all coefficients of this matrix to be equal to DIM x DIM identity matrix.

Definition at line 145 of file matrix.h.

◆ load_zero()

template<index_t DIM, class FT >

void GEO::Matrix< DIM, FT >::load_zero ( )

inline

Clears the matrix.

This resets all values to 0 (zero)

Definition at line 132 of file matrix.h.

◆ operator()() [1/2]

template<index_t DIM, class FT >

FT & GEO::Matrix< DIM, FT >::operator()	(	index_t	i,
		index_t	j
	)

inline

Gets a modifiable element.

Gets element at row i and column j in the matrix. If indices are out of range, the function calls abort().

Parameters

[in]	i	row index of the element
[in]	j	column index of the element

Returns: a reference to the element at coordinates (i, j).

Definition at line 178 of file matrix.h.

◆ operator()() [2/2]

template<index_t DIM, class FT >

const FT & GEO::Matrix< DIM, FT >::operator()	(	index_t	i,
		index_t	j
	)		const

inline

Gets a non-modifiable element.

Gets element at row i and column j in the matrix. If indices are out of range, the function calls abort().

Parameters

[in]	i	row index of the element
[in]	j	column index of the element

Returns: a const reference to the element at coordinates (i, j).

Definition at line 192 of file matrix.h.

◆ operator*() [1/2]

template<index_t DIM, class FT >

matrix_type GEO::Matrix< DIM, FT >::operator* ( const matrix_type & m ) const

inline

Multiplies 2 matrices.

Builds a matrix by multiplying this matrix by matrix m.

Parameters

[in] m another matrix

Returns: the matrix (this * m)

Definition at line 317 of file matrix.h.

◆ operator*() [2/2]

template<index_t DIM, class FT >

matrix_type GEO::Matrix< DIM, FT >::operator* ( FT val ) const

inline

Multiplies a matrix by a scalar.

Builds a matrix by multiplying all the coefficients of this matrix by scalar value val.

Parameters

[in] val a scalar value of the same type than matrix elements

Returns: the resulting matrix

Definition at line 291 of file matrix.h.

◆ operator*=()

template<index_t DIM, class FT >

matrix_type & GEO::Matrix< DIM, FT >::operator*= ( FT val )

inline

Multiplies by a scalar in place.

This multiplies all the coefficients of this matrix by the value val.

Parameters

[in] val a scalar value of the same type than matrix elements

Returns: a reference to this matrix

Definition at line 235 of file matrix.h.

◆ operator+()

template<index_t DIM, class FT >

matrix_type GEO::Matrix< DIM, FT >::operator+ ( const matrix_type & m ) const

inline

Adds 2 matrices.

Builds a matrix by adding matrix m to this matrix.

Parameters

[in] m another matrix

Returns: the matrix (this + m)

Definition at line 266 of file matrix.h.

◆ operator+=()

template<index_t DIM, class FT >

matrix_type & GEO::Matrix< DIM, FT >::operator+= ( const matrix_type & m )

inline

Adds a matrix in place.

This adds matrix m to this matrix in place.

Parameters

[in] m a matrix of the same dimension

Returns: a reference to this matrix

Definition at line 204 of file matrix.h.

◆ operator-()

template<index_t DIM, class FT >

matrix_type GEO::Matrix< DIM, FT >::operator- ( const matrix_type & m ) const

inline

Subtracts 2 matrices.

Builds a matrix by subtracting matrix m to this matrix.

Parameters

[in] m another matrix

Returns: the matrix (this + m)

Definition at line 278 of file matrix.h.

◆ operator-=()

template<index_t DIM, class FT >

matrix_type & GEO::Matrix< DIM, FT >::operator-= ( const matrix_type & m )

inline

Subtracts a matrix in place.

This subtracts matrix m from this matrix in place.

Parameters

[in] m a matrix of the same dimension

Returns: a reference to this matrix

Definition at line 219 of file matrix.h.

◆ operator/()

template<index_t DIM, class FT >

matrix_type GEO::Matrix< DIM, FT >::operator/ ( FT val ) const

inline

Divides a matrix by a scalar.

Builds a matrix by dividing all the coefficients of this matrix by scalar value val.

Parameters

[in] val a scalar value of the same type than matrix elements

Returns: the resulting matrix

Definition at line 304 of file matrix.h.

◆ operator/=()

template<index_t DIM, class FT >

matrix_type & GEO::Matrix< DIM, FT >::operator/= ( FT val )

inline

Divides by a scalar in place.

This divides all the coefficients of this matrix by the value val.

Parameters

[in] val a scalar value of the same type than matrix elements

Returns: a reference to this matrix

Definition at line 251 of file matrix.h.

◆ transpose()

template<index_t DIM, class FT >

matrix_type GEO::Matrix< DIM, FT >::transpose ( ) const

inline

Computes the transposed matrix.

Returns: the transposed matrix

Definition at line 405 of file matrix.h.

Friends And Related Symbol Documentation

◆ mult()

template<index_t DIM, class FT >

void mult	(	const Matrix< DIM, FT > &	M,
		const FT *	x,
		FT *	y
	)

Multiplies matrix M by vector x and stores the result in vector y. Vectors x and y are given as arrays of elements and must at least contain DIM elements, otherwise the result is undefined.

Parameters

[in]	M	a `DIM` x `DIM` matrix
[in]	x	the input vector
[in]	y	the result of the multiplication

Template Parameters

FT	the type of the matrix elements
DIM	the dimension of the matrix

Definition at line 516 of file matrix.h.

◆ operator<<()

template<index_t DIM, class FT >

std::ostream & operator<<	(	std::ostream &	output,
		const Matrix< DIM, FT > &	m
	)

This writes the coefficients of matrix m separated by a space character to the output stream output.

Parameters

[in]	output	the output stream
[in]	m	the matrix to write

Returns: a reference to the output stream output

Definition at line 466 of file matrix.h.

◆ operator>>()

template<index_t DIM, class FT >

std::istream & operator>>	(	std::istream &	input,
		Matrix< DIM, FT > &	m
	)

This reads DIM * DIM coefficients from the input stream input and stores them in matrix m

Parameters

[in]	input	the input stream
[out]	m	the matrix to read

Returns: a reference to the input stream input

Definition at line 489 of file matrix.h.

Member Data Documentation

◆ dim

template<index_t DIM, class FT >

constexpr index_t GEO::Matrix< DIM, FT >::dim = DIM

staticconstexpr

The dimension of the matrix

Definition at line 75 of file matrix.h.

The documentation for this class was generated from the following file:

geogram/basic/matrix.h

Public Types

Public Member Functions

Static Public Attributes

Related Symbols

Detailed Description

Member Typedef Documentation

◆ matrix_type

◆ value_type

Constructor & Destructor Documentation

◆ Matrix() [1/3]

◆ Matrix() [2/3]

◆ Matrix() [3/3]

Member Function Documentation

◆ compute_inverse()

◆ data() [1/2]

◆ data() [2/2]

◆ dimension()

◆ get_lower_triangle()

◆ inverse()

◆ is_identity()

◆ load_identity()

◆ load_zero()

◆ operator()() [1/2]

◆ operator()() [2/2]

◆ operator*() [1/2]

◆ operator*() [2/2]

◆ operator*=()

◆ operator+()

◆ operator+=()

◆ operator-()

◆ operator-=()

◆ operator/()

◆ operator/=()

◆ transpose()

Friends And Related Symbol Documentation

◆ mult()

◆ operator<<()

◆ operator>>()

Member Data Documentation

◆ dim