Matrix_< T > Class Template Reference

Detailed Description

template<class T>
class asl::Matrix_< T >

A matrix supporting basic arithmetic operations.

With two predefined specializations: Matrix for float and Matrixd for double.

Matrix A = {   // this makes a 2x2 matrix
   { 1, -1 },
   { 2, 3 }
};
 
Matrix b = { 5, 1 }; // this makes a column matrix (a vector)

You can operate with matrices:

auto C = A.inverse() * A + b * b.transposed();

And you can solve linear systems, even using least-squares, if more equations than unknowns:

auto x = solve(A, b); // solution to linear system A * x = b

#include <Matrix.h>

Inherits Array2< T >.

Public Member Functions
	Matrix_ (int rows, int cols=1)
	Creates a matrix with size rows x cols.
	Matrix_ (int rows, int cols, const T &value)
	Creates a matrix with size rows x cols and initializes all items with value.
	Matrix_ (int rows, int cols, const T *p)
	Creates a matrix of rows x cols elements and copies them from the pointer p (row-wise)
	Matrix_ (int rows, int cols, std::initializer_list< T > a)
	Creates a matrix with size rows x cols and the given elements.
	Matrix_ (std::initializer_list< std::initializer_list< T > > a)
	Creates a matrix with given list of lists of elements.
	Matrix_ (std::initializer_list< T > a)
	Creates a column matrix with given list of elements.
T	trace () const
	Returns the trace of this matrix.
void	copy (const Matrix_ &b)
	copies the contents of matrix b into this
T &	operator[] (int i)
	Returns the i-th element in memory: useful to treat column or row matrices as vectors.
template<class K >
Matrix_< K >	with () const
	Returns a copy of this matrix with elements converted to the given type.
Matrix_	clone () const
	Returns an independent copy of this matrix.
Matrix_	slice (int i1, int i2, int j1, int j2) const
	Returns a sub-matrix consisting of a rows [i1, i2) and columns [j1, j2)
Matrix_	row (int i) const
	Returns the i-th row.
Matrix_	col (int j) const
	Returns the j-th column.
Matrix_	transposed () const
	Returns this matrix transposed.
Matrix_	inverse () const
	Computes the inverse of this matrix, if it exists; the matrix must be square.
Matrix_	pseudoinverse () const
	Computes the pseudoinverse of this matrix.
Matrix_	operator* (const Matrix_ &b) const
	Computes the product of this matrix and b.
Matrix_	transposed (const Matrix_ &b) const
	Computes the product of this matrix transposed and b (same as A.transposed() * B but a bit faster)
Matrix_	operator+ (const Matrix_ &b) const
	Computes the sum of this matrix and b.
Matrix_	operator- (const Matrix_ &b) const
	Computes the subtraction of this matrix and b.
Matrix_	operator* (T s) const
	Computes the product of this matrix by scalar s.
void	operator+= (const Matrix_ &b)
	Adds a matrix to this.
void	operator-= (const Matrix_ &b)
	Subtracts a matrix from this.
void	operator*= (T s)
	Multiplies this matrix by a scalar.
Matrix_	operator- () const
	Returns this matrix negated (multiplied by -1)
T	normSq () const
	Returns the matrix Frobenius norm squared.
T	norm () const
	Returns the matrix Frobenius norm.
Public Member Functions inherited from Array2< T >
	Array2 ()
	Creates an empty array.
	Array2 (int rows, int cols)
	Creates an array with size rows x cols.
	Array2 (int rows, int cols, const T &value)
	Creates an array with size rows x cols and initializes all items with value.
	Array2 (int rows, int cols, const T *p)
	Creates an array of rows x cols elements and copies them from the pointer p (row-wise)
	Array2 (int rows, int cols, std::initializer_list< T > a)
	Creates an array with size rows x cols and the given elements.
	Array2 (std::initializer_list< std::initializer_list< T > > a)
	Creates an array with given list of lists of elements.
template<class K >
Array2< K >	with () const
	Creates a copy of this array with items converted to type K.
Array< T > &	data ()
	Returns the internal array holding all values (row-major)
const Array< T > &	data () const
	Returns the internal array holding all values (row-major)
Array< T > &	array ()
	Returns the internal array holding all values (row-major)
const Array< T > &	array () const
	Returns the internal array holding all values (row-major)
bool	operator== (const Array2 &b) const
	Returns true if both arrays are equal.
bool	operator!= (const Array2 &b) const
	Returns true if both arrays are not equal.
Array2	clone () const
	Returns an independent copy of this array.
Array2	slice (int i1, int i2, int j1, int j2) const
	Returns a sub-array consisting of a rows [i1, i2) and columns [j1, j2)
Array2 &	resize (int r, int c)
	Resizes the matrix to r x c.
int	rows () const
	Returns the number of rows.
int	cols () const
	Returns the number of columns.
T &	operator() (int i, int j)
	Returns the item at row i, column j.
void	set (const T &x)
	Sets all array items to value x.

Static Public Member Functions
static Matrix_	identity (int n)
	Returns an identity matrix of the given size.

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

• Matrix.h