One such multidimensional extension of Eigen is from Google and I believe was extracted from TensorFlow: https://bitbucket.org/eigen/eigen/src/039efd86b75ce1b7

One such multidimensional extension of Eigen is from Google and I believe was extracted from TensorFlow: https://bitbucket.org/eigen/eigen/src/039efd86b75ce1b72befb7e0a5bd069baacb17b7/unsupported/Eigen/CXX11/src/Tensor/README.md?fileviewer=file-view-default https://bitbucket.org/eigen/eigen/src/039efd86b75ce1b72befb7...