import org.jblas.DoubleMatrix; public class MatrixCalculation { public static void main(String[] args) { DoubleMatrix matrix1 = new DoubleMatrix(new double[][]{{1, 2, 3}, {4, 5, 6}, {7, 8, 9}}); DoubleMatrix matrix2 = new DoubleMatrix(new double[][]{{9, 8, 7}, {6, 5, 4}, {3, 2, 1}}); DoubleMatrix sumMatrix = matrix1.add(matrix2); System.out.println(sumMatrix); DoubleMatrix mulMatrix = matrix1.mmul(matrix2); System.out.println(mulMatrix); } }