dotProduct() public méthode

Dot product (inner product) (A⋅B) https://en.wikipedia.org/wiki/Dot_product
public dotProduct ( Vector $B ) : number
$B Vector
Résultat number
Vector Class Documentation
Exemple #1
0
 /**
  * Matrix multiplication
  * https://en.wikipedia.org/wiki/Matrix_multiplication#Matrix_product_.28two_matrices.29
  *
  * @param  Matrix/Vector $B Matrix or Vector to multiply
  *
  * @return Matrix
  *
  * @throws IncorrectTypeException if parameter B is not a Matrix or Vector
  * @throws MatrixException if matrix dimensions do not match
  */
 public function multiply($B) : Matrix
 {
     if (!$B instanceof Matrix && !$B instanceof Vector) {
         throw new Exception\IncorrectTypeException('Can only do matrix multiplication with a Matrix or Vector');
     }
     if ($B instanceof Vector) {
         $B = $B->asColumnMatrix();
     }
     if ($B->getM() !== $this->n) {
         throw new Exception\MatrixException("Matrix dimensions do not match");
     }
     $n = $B->getN();
     $m = $this->m;
     $R = [];
     for ($i = 0; $i < $m; $i++) {
         for ($j = 0; $j < $n; $j++) {
             $VA = new Vector($this->getRow($i));
             $VB = new Vector($B->getColumn($j));
             $R[$i][$j] = $VA->dotProduct($VB);
         }
     }
     return MatrixFactory::create($R);
 }