Unfit::Matrix Class Reference

#include <Matrix.hpp>

Public Member Functions
	Matrix ()
	Matrix (std::size_t num_rows, std::size_t num_cols, double the_value)
	Matrix (std::size_t num_rows, std::size_t num_cols, const std::vector< double > &the_values)
void	Assign (std::size_t num_rows, std::size_t num_cols, double the_value)
void	Assign (std::size_t num_rows, std::size_t num_cols, const std::vector< double > &matrix_values)
double	GetValue (std::size_t row, std::size_t col) const noexcept
void	SetValue (std::size_t row, std::size_t col, double the_value)
std::size_t	GetNumberOfColumns () const noexcept
std::size_t	GetNumberOfRows () const noexcept
std::size_t	Size () const noexcept
bool	Empty () const noexcept
void	AddConstantToDiagonal (double value, std::size_t offset=0, bool upper_triangle=true)

Public Attributes
std::vector< double >	values_

Private Attributes
std::size_t	number_of_rows_
std::size_t	number_of_columns_

Detailed Description

A class to store and operate on a 2D matrix. The matrix does not have to be square. The data is stored in a 1D vector row-wise.

Constructor & Destructor Documentation

Matrix() [1/3]

Unfit::Matrix::Matrix

(

)

Constructor: (default) Override the default constructor to set the number of rows and columns to zero explicitly so we can't access any entries by accident.

Matrix() [2/3]

Unfit::Matrix::Matrix	(	std::size_t	num_rows,
		std::size_t	num_cols,
		double	the_value
	)

Constructor: Creates a matrix with the specified dimensions (num_rows x num_cols) and initialises each of the entries to a constant value. This constant must be the same value type as is specified in the matrix template.

Parameters

num_rows	the number of rows in the resulting matrix
num_cols	the number of columns in the resulting matrix
the_value	a constant value to be assigned to all matrix entries

Matrix() [3/3]

Unfit::Matrix::Matrix	(	std::size_t	num_rows,
		std::size_t	num_cols,
		const std::vector< double > &	the_values
	)

Constructor: Creates a matrix with the specified dimensions (number_of_rows x number_of_columns) from a std::vector. Note that this does a copy construction such that the vector of values that was passed in remains unchanged. This is not as fast as a move construction via std::move, especially for large objects, but I suspect that this is the behaviour most users would expect. The vector of values must have the same value type as is specified in the matrix template.

Parameters

num_rows	the number of rows in the resulting matrix
num_cols	the number of columns in the resulting matrix
the_values	a constant value to be assigned to all matrix entries

Member Function Documentation

AddConstantToDiagonal()

void Unfit::Matrix::AddConstantToDiagonal	(	double	value,
		std::size_t	offset = 0,
		bool	upper_triangle = true
	)

Add a given value to a matrix diagonal. If offset is 0 (the default value), this method will set the values along the main (leading) diagonal. Otherwise, if an offset of "n" is specified, it will set the values along the nth sub-diagonal. By default, the diagonal values will be set in the upper triangular part of the matrix, meaning that the offset represents a number of columns. If the diagonal of interest is in the lower triangular part of the matrix then just set the upper_triangular boolean to false. In this case the offset represents a number of rows. If an offset is specified that is larger than the matrix dimensions no values in the matrix are changed. If the offset is zero it does not matter if the upper_triangular argument is true or not. The value type for the new values must be the same as the value type in the matrix. Note that the matrix coordinates start from (0,0).

Parameters

value	the value to be set on the diagonal
offset	the distance from the main diagonal (optional, default = 0 = main diagonal)
upper_triangle	elect the direction for the offset (optional, default = true = upper triangle)

Assign() [1/2]

void Unfit::Matrix::Assign	(	std::size_t	num_rows,
		std::size_t	num_cols,
		double	the_value
	)

This method assigns and resizes the matrix to the corrected dimensions

Parameters

num_rows	the new number of rows in the resulting matrix
num_cols	the new number of columns in the resulting matrix
the_value	the value to be inserted into the matrix

Assign() [2/2]

void Unfit::Matrix::Assign	(	std::size_t	num_rows,
		std::size_t	num_cols,
		const std::vector< double > &	matrix_values
	)

This method assigns and resizes the matrix to the corrected dimensions

Parameters

num_rows	the new number of rows in the resulting matrix
num_cols	the new number of columns in the resulting matrix
matrix_values	the matrix vector to be inserted into the matrix

Empty()

bool Unfit::Matrix::Empty ( ) const

noexcept

Get the number of entries in the stored matrix.

Returns

the number entries in the matrix

GetNumberOfColumns()

std::size_t Unfit::Matrix::GetNumberOfColumns ( ) const

noexcept

Get the number of columns in the stored matrix. The entries will be stored from 0 to rows-1.

Returns

the number columns in the matrix

GetNumberOfRows()

std::size_t Unfit::Matrix::GetNumberOfRows ( ) const

noexcept

Get the number of rows in the stored matrix. The entries will be stored from 0 to cols-1.

Returns

the number rows in the matrix

GetValue()

double Unfit::Matrix::GetValue ( std::size_t  row, std::size_t  col  ) const

noexcept

Get the value stored in the matrix at the position (row,column). Note: The matrix coordinates start from (0,0).

Parameters

row	the row number of the requested value
col	the column number of the requested value

Returns

the value of the matrix at position (row,column)

SetValue()

void Unfit::Matrix::SetValue	(	std::size_t	row,
		std::size_t	col,
		double	the_value
	)

Set the value stored in the matrix at the position (row,column). Note: The matrix coordinates start from (0,0).

Parameters

row	the row number of the requested value
col	the column number of the requested value
the_value	the value to be placed at (row,column)

Size()

std::size_t Unfit::Matrix::Size ( ) const

noexcept

Get the number of entries in the stored matrix.

Returns

the number entries in the matrix

Member Data Documentation

number_of_columns_

std::size_t Unfit::Matrix::number_of_columns_

private

Number of columns in the matrix

number_of_rows_

std::size_t Unfit::Matrix::number_of_rows_

private

Number of rows in the matrix

values_

std::vector<double> Unfit::Matrix::values_

Matrix entries stored row-wise in a 1D vector. Note that these values are public to allow direct (fast) access. This is fine for reading, but if you are writing here directly it is up to you to check you are within the bounds of the matrix.

---

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

• include/Matrix.hpp
• src/Matrix.cpp