1MatrixXd X = MatrixXd::Random(4,4); 2MatrixXd A = X * X.transpose(); 3cout << "Here is a random positive-definite matrix, A:" << endl << A << endl << endl; 4 5SelfAdjointEigenSolver<MatrixXd> es(A); 6cout << "The inverse square root of A is: " << endl; 7cout << es.operatorInverseSqrt() << endl; 8cout << "We can also compute it with operatorSqrt() and inverse(). That yields: " << endl; 9cout << es.operatorSqrt().inverse() << endl; 10