src/Chippyash/Math/Matrix/Computation/Sub/Scalar.php
<?php
/*
* Math-Matrix library
*
* @author Ashley Kitson <akitson@zf4.biz>
* @copyright Ashley Kitson, UK, 2014
* @licence GPL V3 or later : http://www.gnu.org/licenses/gpl.html
* @link http://en.wikipedia.org/wiki/Matrix_(mathematics)
*/
namespace Chippyash\Math\Matrix\Computation\Sub;
use Chippyash\Math\Matrix\Computation\AbstractComputation;
use Chippyash\Math\Matrix\NumericMatrix;
use Chippyash\Math\Matrix\Traits\CreateCorrectMatrixType;
use Chippyash\Math\Matrix\Traits\CreateCorrectScalarType;
use Chippyash\Math\Type\Calculator;
/**
* Subtract a scalar from every item in the operand matrix
* @link http://www.php.net//manual/en/function.is-scalar.php
*/
class Scalar extends AbstractComputation
{
use CreateCorrectMatrixType;
use CreateCorrectScalarType;
/**
* Subtract a single scalar value from each member of the matrix and return result
* Boolean values are converted to 0 (false) and 1 (true). Use the logical
* computations if required.
* String values do a string replace for the scalar, replacing occurences of
* if with ''
*
* @param NumericMatrix $mA First matrix to act on - required
* @param scalar $extra value to subtract
*
* @return Matrix
*
* @throws Chippyash/Matrix/Exceptions/ComputationException
*/
public function compute(NumericMatrix $mA, $extra = null)
{
if ($mA->is('empty')) {
return $this->createCorrectMatrixType($mA);
}
$scalar = $this->createCorrectScalarType($mA, $extra);
$data = $mA->toArray();
$lx = $mA->columns();
$ly = $mA->rows();
$calc = new Calculator();
for ($row = 0; $row < $ly; $row++) {
for ($col = 0; $col < $lx; $col++) {
$data[$row][$col] = $calc->sub($data[$row][$col], $scalar);
}
}
return $this->createCorrectMatrixType($mA, $data);
}
}