#includeint main() { Eigen::MatrixXf A(5, 5); Eigen::MatrixXf submatrix; // initialize A submatrix = A.rows(1, 3); // gets the rows 1 to 3 inclusive }
#includeIn this example, `MatrixXf.rows()` is used indirectly to loop through each row of `A` and output its contents. The function `A.row(i)` returns a row vector from `A` at index `i`. Overall, `MatrixXf.rows()` is a useful function for accessing or modifying specific blocks of rows in a matrix. It is part of the Eigen library, which is a popular package for linear algebra operations in C++.#include int main() { Eigen::MatrixXf A(5, 3); // initialize A for (int i = 0; i < A.rows(); ++i) { std::cout << "Row " << i << ":\n"; std::cout << A.row(i) << "\n\n"; } }