Most efficient option for build 3D structures using Eigen matrices

Question

I need a 3D matrix/array structure on my code, and right now I\'m relying on Eigen for both my matrices and vectors.

Right now I am creating a 3D structure using

Answer 1

While it was not available, when the question was asked, Eigen has been providing a Tensor module for a while now. It is still in an "unsupported" stage (meaning the API may change), but basic functionality should be mostly stable. The documentation is scattered here and here.