HP MLIB User's Guide Vol. 2 7th Ed.

996 HP MLIB User’s Guide
mlib_METIS_NodeWND Computes fill reducing orderings of sparse matrices
and RM is slower, but feel free to experiment with the
other matching schemes.
options[2] Determines the algorithm used during
initial partioning. Possible values are:
1—Edge-based region growing (Default)
2—Node-based region growing
options[3] Determines the algorithm used for
refinement. Possible values are:
1—Two-sided node FM refinement
2—One-sided node FM refinement (Default)
One-sided FM refinement is faster than two-sided, but
in some cases two-sided refinement may produce better
orderings.
options[4] Used for debugging purposes. Always set it
to 0 (Default)
perm,
iperm
These are vectors, each of size n. Upon successful
completion, they store the fill-reducing permutation
and inverse-permutation. Let A be the original matrix
and A' be the permuted matrix. The arrays perm and
iperm are defined as follows: Row (column) i of A' is the
perm[i] row (column) of A, and row (column) i of A is
the iperm[i] row (column) of A'. The numbering of this
vector starts from either 0 or 1, depending on the value
of numflag.