<?php
/**
*
* Class for the management of Matrices
*
* @copyright Copyright (c) 2018 Mark Baker (https://github.com/MarkBaker/PHPMatrix)
* @license https://opensource.org/licenses/MIT MIT
*/
namespace Matrix;
use Generator;
use Matrix\Decomposition\LU;
use Matrix\Decomposition\QR;
/**
* Matrix object.
*
* @package Matrix
*
* @property-read int $rows The number of rows in the matrix
* @property-read int $columns The number of columns in the matrix
* @method Matrix antidiagonal()
* @method Matrix adjoint()
* @method Matrix cofactors()
* @method float determinant()
* @method Matrix diagonal()
* @method Matrix identity()
* @method Matrix inverse()
* @method Matrix minors()
* @method float trace()
* @method Matrix transpose()
* @method Matrix add(...$matrices)
* @method Matrix subtract(...$matrices)
* @method Matrix multiply(...$matrices)
* @method Matrix divideby(...$matrices)
* @method Matrix divideinto(...$matrices)
* @method Matrix directsum(...$matrices)
*/
class Matrix
{
protected $rows;
protected $columns;
protected $grid = [];
/*
* Create a new Matrix object from an array of values
*
* @param array $grid
*/
final public function __construct(array $grid)
{
$this->buildFromArray(array_values($grid));
}
/*
* Create a new Matrix object from an array of values
*
* @param array $grid
*/
protected function buildFromArray(array $grid): void
{
$this->rows = count($grid);
$columns = array_reduce(
$grid,
function ($carry, $value) {
return max($carry, is_array($value) ? count($value) : 1);
}
);
$this->columns = $columns;
array_walk(
$grid,
function (&$value) use ($columns) {
if (!is_array($value)) {
$value = [$value];
}
$value = array_pad(array_values($value), $columns, null);
}
);
$this->grid = $grid;
}
/**
* Validate that a row number is a positive integer
*
* @param int $row
* @return int
* @throws Exception
*/
public static function validateRow(int $row): int
{
if ((!is_numeric($row)) || (intval($row) < 1)) {
throw new Exception('Invalid Row');
}
return (int)$row;
}
/**
* Validate that a column number is a positive integer
*
* @param int $column
* @return int
* @throws Exception
*/
public static function validateColumn(int $column): int
{
if ((!is_numeric($column)) || (intval($column) < 1)) {
throw new Exception('Invalid Column');
}
return (int)$column;
}
/**
* Validate that a row number falls within the set of rows for this matrix
*
* @param int $row
* @return int
* @throws Exception
*/
protected function validateRowInRange(int $row): int
{
$row = static::validateRow($row);
if ($row > $this->rows) {
throw new Exception('Requested Row exceeds matrix size');
}
return $row;
}
/**
* Validate that a column number falls within the set of columns for this matrix
*
* @param int $column
* @return int
* @throws Exception
*/
protected function validateColumnInRange(int $column): int
{
$column = static::validateColumn($column);
if ($column > $this->columns) {
throw new Exception('Requested Column exceeds matrix size');
}
return $column;
}
/**
* Return a new matrix as a subset of rows from this matrix, starting at row number $row, and $rowCount rows
* A $rowCount value of 0 will return all rows of the matrix from $row
* A negative $rowCount value will return rows until that many rows from the end of the matrix
*
* Note that row numbers start from 1, not from 0
*
* @param int $row
* @param int $rowCount
* @return static
* @throws Exception
*/
public function getRows(int $row, int $rowCount = 1): Matrix
{
$row = $this->validateRowInRange($row);
if ($rowCount === 0) {
$rowCount = $this->rows - $row + 1;
}
return new static(array_slice($this->grid, $row - 1, (int)$rowCount));
}
/**
* Return a new matrix as a subset of columns from this matrix, starting at column number $column, and $columnCount columns
* A $columnCount value of 0 will return all columns of the matrix from $column
* A negative $columnCount value will return columns until that many columns from the end of the matrix
*
* Note that column numbers start from 1, not from 0
*
* @param int $column
* @param int $columnCount
* @return Matrix
* @throws Exception
*/
public function getColumns(int $column, int $columnCount = 1): Matrix
{
$column = $this->validateColumnInRange($column);
if ($columnCount < 1) {
$columnCount = $this->columns + $columnCount - $column + 1;
}
$grid = [];
for ($i = $column - 1; $i < $column + $columnCount - 1; ++$i) {
$grid[] = array_column($this->grid, $i);
}
return (new static($grid))->transpose();
}
/**
* Return a new matrix as a subset of rows from this matrix, dropping rows starting at row number $row,
* and $rowCount rows
* A negative $rowCount value will drop rows until that many rows from the end of the matrix
* A $rowCount value of 0 will remove all rows of the matrix from $row
*
* Note that row numbers start from 1, not from 0
*
* @param int $row
* @param int $rowCount
* @return static
* @throws Exception
*/
public function dropRows(int $row, int $rowCount = 1): Matrix
{
$this->validateRowInRange($row);
if ($rowCount === 0) {
$rowCount = $this->rows - $row + 1;
}
$grid = $this->grid;
array_splice($grid, $row - 1, (int)$rowCount);
return new static($grid);
}
/**
* Return a new matrix as a subset of columns from this matrix, dropping columns starting at column number $column,
* and $columnCount columns
* A negative $columnCount value will drop columns until that many columns from the end of the matrix
* A $columnCount value of 0 will remove all columns of the matrix from $column
*
* Note that column numbers start from 1, not from 0
*
* @param int $column
* @param int $columnCount
* @return static
* @throws Exception
*/
public function dropColumns(int $column, int $columnCount = 1): Matrix
{
$this->validateColumnInRange($column);
if ($columnCount < 1) {
$columnCount = $this->columns + $columnCount - $column + 1;
}
$grid = $this->grid;
array_walk(
$grid,
function (&$row) use ($column, $columnCount) {
array_splice($row, $column - 1, (int)$columnCount);
}
);
return new static($grid);
}
/**
* Return a value from this matrix, from the "cell" identified by the row and column numbers
* Note that row and column numbers start from 1, not from 0
*
* @param int $row
* @param int $column
* @return mixed
* @throws Exception
*/
public function getValue(int $row, int $column)
{
$row = $this->validateRowInRange($row);
$column = $this->validateColumnInRange($column);
return $this->grid[$row - 1][$column - 1];
}
/**
* Returns a Generator that will yield each row of the matrix in turn as a vector matrix
* or the value of each cell if the matrix is a column vector
*
* @return Generator|Matrix[]|mixed[]
*/
public function rows(): Generator
{
foreach ($this->grid as $i => $row) {
yield $i + 1 => ($this->columns == 1)
? $row[0]
: new static([$row]);
}
}
/**
* Returns a Generator that will yield each column of the matrix in turn as a vector matrix
* or the value of each cell if the matrix is a row vector
*
* @return Generator|Matrix[]|mixed[]
*/
public function columns(): Generator
{
for ($i = 0; $i < $this->columns; ++$i) {
yield $i + 1 => ($this->rows == 1)
? $this->grid[0][$i]
: new static(array_column($this->grid, $i));
}
}
/**
* Identify if the row and column dimensions of this matrix are equal,
* i.e. if it is a "square" matrix
*
* @return bool
*/
public function isSquare(): bool
{
return $this->rows === $this->columns;
}
/**
* Identify if this matrix is a vector
* i.e. if it comprises only a single row or a single column
*
* @return bool
*/
public function isVector(): bool
{
return $this->rows === 1 || $this->columns === 1;
}
/**
* Return the matrix as a 2-dimensional array
*
* @return array
*/
public function toArray(): array
{
return $this->grid;
}
/**
* Solve A*X = B.
*
* @param Matrix $B Right hand side
*
* @throws Exception
*
* @return Matrix ... Solution if A is square, least squares solution otherwise
*/
public function solve(Matrix $B): Matrix
{
if ($this->columns === $this->rows) {
return (new LU($this))->solve($B);
}
return (new QR($this))->solve($B);
}
protected static $getters = [
'rows',
'columns',
];
/**
* Access specific properties as read-only (no setters)
*
* @param string $propertyName
* @return mixed
* @throws Exception
*/
public function __get(string $propertyName)
{
$propertyName = strtolower($propertyName);
// Test for function calls
if (in_array($propertyName, self::$getters)) {
return $this->$propertyName;
}
throw new Exception('Property does not exist');
}
protected static $functions = [
'adjoint',
'antidiagonal',
'cofactors',
'determinant',
'diagonal',
'identity',
'inverse',
'minors',
'trace',
'transpose',
];
protected static $operations = [
'add',
'subtract',
'multiply',
'divideby',
'divideinto',
'directsum',
];
/**
* Returns the result of the function call or operation
*
* @param string $functionName
* @param mixed[] $arguments
* @return Matrix|float
* @throws Exception
*/
public function __call(string $functionName, $arguments)
{
$functionName = strtolower(str_replace('_', '', $functionName));
// Test for function calls
if (in_array($functionName, self::$functions, true)) {
return Functions::$functionName($this, ...$arguments);
}
// Test for operation calls
if (in_array($functionName, self::$operations, true)) {
return Operations::$functionName($this, ...$arguments);
}
throw new Exception('Function or Operation does not exist');
}
}
Discover the Latest in Digital Payments and NFC Technology
Dive into our blog to explore the cutting-edge trends in digital payments and NFC technology. Stay updated on the innovations that are revolutionizing transactions, boosting security, and making payments quicker and more convenient. Learn how these advancements are shaping the future of financial interactions and driving the global transition towards a cashless world.
The Rise of Contactless Payments:...
In recent years, contactless payments have surged in popularity, driven...
Enhancing Payment Security: The Role...
As digital transactions proliferate, ensuring robust payment security is more critical than ever. Two foundational...
The Future of Digital Wallets:...
Digital wallets have fundamentally transformed how we manage money, offering a streamlined, secure, and highly...
In the digital age, privacy concerns have become increasingly paramount, prompting the European Union to enact the General Data Protection Regulation (GDPR) in 2018. Among its many provisions, GDPR sets strict guidelines for the collection and processing of personal data, including the use of cookies on websites. Privacy Policy
