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<?php |
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declare (strict_types=1); |
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namespace Np\linAlgb\decompositions; |
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use Np\matrix; |
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use Np\vector; |
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use Np\core\lapack; |
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/** |
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* SVD |
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* Compute the singular value decomposition of a matrix and |
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* return an object of the singular values and unitary matrices |
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* |
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* @package Np |
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* @category Scientific Library for Php |
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* @author ghost (Shubham Chaudhary) |
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* @email [email protected] |
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* @copyright (c) 2020-2021, Shubham Chaudhary |
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*/ |
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class svd { |
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/** |
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* |
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* @param matrix $m |
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* @return self |
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*/ |
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public static function factory(\Np\matrix $m): self { |
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$k = min($m->row, $m->col); |
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$ar = $m->copy(); |
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$s = vector::factory($k); |
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$u = matrix::factory($m->row, $m->row); |
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$v = matrix::factory($m->col, $m->col); |
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$lp = lapack::gesdd($ar, $s, $u, $v); |
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if ($lp != 0) { |
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return null; |
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} |
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unset($ar); |
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unset($k); |
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unset($lp); |
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return new self($u, $v, $s); |
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} |
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/** |
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* |
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* @param \Np\matrix $u |
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* @param \Np\matrix $v |
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* @param \Np\vector $s |
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*/ |
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protected function __construct(protected \Np\matrix $u, protected \Np\matrix $v, protected \Np\vector $s) { |
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} |
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/** |
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* Return the U matrix. |
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* |
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* @return matrix |
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*/ |
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public function u(): matrix { |
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return $this->u; |
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} |
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/** |
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* Return the singular values of matrix. |
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* |
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* @return vector |
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*/ |
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public function s(): vector { |
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return $this->s; |
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} |
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/** |
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* Return the V matrix. |
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* |
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* @return matrix |
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*/ |
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public function v(): matrix { |
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return $this->v; |
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} |
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/** |
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* Return the V transposed matrix. |
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* |
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* @return matrix |
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*/ |
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public function vt(): matrix { |
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return $this->v->transpose(); |
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} |
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} |
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ghostjat /
Np
