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<?php |
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declare(strict_types=1); |
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namespace Np\linAlgb; |
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use Np\core\{blas,lapack}; |
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use Np\matrix, Np\vector; |
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/** |
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* Linear Algebra |
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* |
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* |
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* |
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* @package Np |
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* @category Scientific Computing |
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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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trait linAlg { |
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/** |
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* |
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* get dot product of m.m | m.v | v.v |
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* |
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* @param \Np\matrix|\Np\vector $d |
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* @return matrix|vector |
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*/ |
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public function dot(matrix|vector $d): matrix|vector { |
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if ($this instanceof matrix) { |
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if ($d instanceof matrix) { |
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return $this->dotMatrix($d); |
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} |
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return $this->dotVector($d); |
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} |
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return blas::dot($this, $d); |
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} |
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/** |
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* get matrix & matrix dot product |
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* @param \Np\matrix $matrix |
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* @return \Np\matrix |
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*/ |
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protected function dotMatrix(matrix $matrix): matrix { |
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if ($this->checkDimensions($this,$matrix)) { |
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$ar = self::factory($this->row, $matrix->col); |
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blas::gemm($this, $matrix, $ar); |
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return $ar; |
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} |
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} |
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/** |
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* get dot product of matrix & a vector |
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* @param \Np\vector $vector |
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* @return \Np\vector |
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*/ |
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protected function dotVector(vector $vector): vector { |
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if ($this->checkDimensions($vector, $this)) { |
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$mvr = vector::factory($this->col); |
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blas::gemv($this, $vector, $mvr); |
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return $mvr; |
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} |
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} |
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/** |
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* |
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* Compute the multiplicative inverse of the matrix. |
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* @return matrix|null |
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*/ |
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public function inverse(): matrix|null { |
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if ($this->isSquare()) { |
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$imat = $this->copy(); |
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$ipiv = vector::factory($this->row, vector::INT); |
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$lp = lapack::getrf($imat, $ipiv); |
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if ($lp != 0) { |
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return null; |
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} |
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$lp = lapack::getri($imat, $ipiv); |
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if ($lp != 0) { |
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return null; |
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} |
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unset($ipiv); |
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unset($lp); |
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return $imat; |
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} |
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self::_err('Error::invalid Size of matrix!'); |
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} |
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/** |
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* FIXEME:-Bug noticed on 10/06/21 |
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* Compute the (Moore-Penrose) pseudo inverse of the general matrix. |
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* @return matrix|null |
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*/ |
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public function pseudoInverse(): matrix|null { |
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$k = min($this->row, $this->col); |
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$s = vector::factory($k); |
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$u = self::factory($this->row, $this->row); |
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$vt = self::factory($this->col, $this->col); |
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$imat = $this->copy(); |
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$lp = lapack::gesdd($imat, $s, $u, $vt); |
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if ($lp != 0) { |
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return null; |
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} |
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for ($i = 0; $i < $k; ++$i) { |
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blas::scale(1.0 / $s->data[$i], $vt->rowAsVector($i)); |
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} |
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unset($imat); |
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unset($k); |
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unset($lp); |
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unset($s); |
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$mr = self::factory($this->col, $this->row, $this->dtype); |
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blas::gemm($vt, $u, $mr); |
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unset($u); |
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unset($vt); |
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return $mr; |
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} |
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} |
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For hinted functions/methods where all return statements with the correct type are only reachable via conditions, ?null? gets implicitly returned which may be incompatible with the hinted type. Let?s take a look at an example: