std::vector to Eigen::MatrixXd Eigen

Question

I would like to know whether is there an easier way to solve my problem rather than use a for loop. So here is the situation:

In general, I would like to gather data

Answer 1

This solution should work:

Eigen::MatrixXd sensor_input = Eigen::MatrixXd::Map(sensor_input_vector[0].data(),
 3, sensor_input_vector.size());

Since your output will be a matrix of 3 x N (N is the number of 3D vectors), you could use the Map function of Eigen::Matrix3Xd too:

Eigen::Matrix3Xd sensor_input = Eigen::Matrix3Xd::Map(sensor_input_vector[0].data(),
 3, sensor_input_vector.size());