Hi all,

I would like to explore a little bit on using Eigen in a MPI application. This evolves using "ghost points" for data transfer across processes. The syntax would be better and more readable if the index for member accessing starts from a negative value.

For example,

MatrixXf m(4, 4);

m(-1, 2) -> ghost point
m(0, 2) -> this is where the "real" data starts.

Could you suggest a good way to do this?

Thanks,
Cheng