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

994 HP MLIB User’s Guide

mlib_METIS_NodeND Computes ﬁll reducing orderings of sparse matrices

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.

Notes This function computes the vertex separator by using a multilevel algorithm.

This function produces high quality orderings and should be preferred over

mlib_METIS_EdgeND.