template<typename StorageIndex>
class Eigen::MetisOrdering< StorageIndex >

Get the fill-reducing ordering from the METIS package

If A is the original matrix and Ap is the permuted matrix, the fill-reducing permutation is defined as follows : Row (column) i of A is the matperm(i) row (column) of Ap. WARNING: As computed by METIS, this corresponds to the vector iperm (instead of perm)