code: public static DoubleMatrix gemm(double alpha, DoubleMatrix a,
  			DoubleMatrix b, double beta, DoubleMatrix c) {
  		NativeBlas.dgemm('N', 'N', c.rows, c.columns, a.columns, alpha, a.data, 0,
  				a.rows, b.data, 0, b.rows, beta, c.data, 0, c.rows);
  		return c;
  	}
docs: Compute c <- a*b + beta * c (general matrix matrix
  multiplication)