I'm interested in forming a square submatrix from another dynamic size matrix in Eigen, by specifying explicitly the indices.
In particular, what is the Eigen equivalent of this operation in Matlab/Octave?

Code: Select all

A=magic(6);
ind=[1,4,5,6];
A(ind,ind)


I can't understand how to do that using blocks or views.
A view would be the best option, because it is not necessary to create temporary matrices.