1MatrixXf mat(2,2); 2mat << 1, 2, 4, 7; 3cout << "Here is the matrix mat:\n" << mat << endl << endl; 4 5mat = 2 * mat; 6cout << "After 'mat = 2 * mat', mat = \n" << mat << endl << endl; 7 8 9mat = mat - MatrixXf::Identity(2,2); 10cout << "After the subtraction, it becomes\n" << mat << endl << endl; 11 12 13ArrayXXf arr = mat; 14arr = arr.square(); 15cout << "After squaring, it becomes\n" << arr << endl << endl; 16 17// Combining all operations in one statement: 18mat << 1, 2, 4, 7; 19mat = (2 * mat - MatrixXf::Identity(2,2)).array().square(); 20cout << "Doing everything at once yields\n" << mat << endl << endl; 21