public function getU()
    {
        return new Matrix($this->U, $this->m, min($this->m + 1, $this->n));
    }
public function getU()
    {
        return new Matrix($this->U, $this->m, min($this->m + 1, $this->n));
    }
public function getU ( ) { return new Matrix ( $ this -> U , $ this -> m , min ( $ this -> m + 1 , $ this -> n ) ) ; }
Return the left singular vectors

@access public
@return U
Return the left singular vectors