1 MatrixXf matA(2,2), matB(2,2); 2 matA << 2, 0, 0, 2; 3 4 // Simple but not quite as efficient 5 matB = matA * matA; 6 cout << matB << endl << endl; 7 8 // More complicated but also more efficient 9 matB.noalias() = matA * matA; 10 cout << matB; 11