import Jama.Matrix; public class JamaExample { public static void main(String[] args) { double[][] array = {{1, 2}, {3, 4}}; Matrix matrix = new Matrix(array); matrix.print(); double[][] array2 = {{5, 6}, {7, 8}}; Matrix matrix2 = new Matrix(array2); Matrix matrixSum = matrix.plus(matrix2); matrixSum.print(); Matrix matrixProduct = matrix.times(matrix2); matrixProduct.print(); } }