/**
* Multiplies two matrices
*
* Multiply current matrix with another matrix and returns the result
* matrix.
*
* @param ezcGraphMatrix $matrix Second factor
* @return ezcGraphMatrix Result matrix
*/
public function multiply(ezcGraphMatrix $matrix)
{
$mColumns = $matrix->columns();
// We want to ensure, that the matrix stays 3x3
if ($this->columns !== $matrix->rows() && $this->rows !== $mColumns) {
throw new ezcGraphMatrixInvalidDimensionsException($this->columns, $this->rows, $mColumns, $matrix->rows());
}
$result = parent::multiply($matrix);
// The matrix dimensions stay the same, so that we can modify $this.
for ($i = 0; $i < $this->rows; ++$i) {
for ($j = 0; $j < $mColumns; ++$j) {
$this->set($i, $j, $result->get($i, $j));
}
}
return $this;
}
/**
* Multiplies two matrices
*
* Multiply current matrix with another matrix and returns the result
* matrix.
*
* @param ezcGraphMatrix $matrix Second factor
* @return ezcGraphMatrix Result matrix
*/
public function multiply(ezcGraphMatrix $matrix)
{
$mColumns = $matrix->columns();
if ($this->columns !== ($mRows = $matrix->rows())) {
throw new ezcGraphMatrixInvalidDimensionsException($this->columns, $this->rows, $mColumns, $mRows);
}
$result = new ezcGraphMatrix($this->rows, $mColumns);
for ($i = 0; $i < $this->rows; ++$i) {
for ($j = 0; $j < $mColumns; ++$j) {
$sum = 0;
for ($k = 0; $k < $mRows; ++$k) {
$sum += $this->matrix[$i][$k] * $matrix->get($k, $j);
}
$result->set($i, $j, $sum);
}
}
return $result;
}
