std::vector 到 Eigen::VectorXf

Question

I have a vector

int N = 100;
std::vector<float> v(N, 1.0f);

which I'd like to convert to an Eigen vector type ( Eigen::VectorXf ?) I have tried

Eigen::VectorXf ev(N);  
ev = Eigen::Map<Eigen::VectorXf>(&v[0], N);

but I am not sure if it right or wrong. I can only see ev has 1 value in my visual studio.

Answer 1

Your code seems correct. No need to initialize ev(N) , though. You can just write

Eigen::VectorXf ev = Eigen::VectorXf::Map(&v[0], N);