| DEFUN_DLD (symrcm, args,,"-*- texinfo -*-\n\
@deftypefn {Loadable Function} {@var{p} =} symrcm (@var{S})\n\
Return the symmetric reverse Cuthill-McKee permutation of @var{S}.\n\
@var{p} is a permutation vector such that\n\
@code{@var{S}(@var{p}, @var{p})} tends to have its diagonal elements\n\
closer to the diagonal than @var{S}. This is a good preordering for LU\n\
or Cholesky@tie{}factorization of matrices that come from 'long, skinny'\n\
problems. It works for both symmetric and asymmetric @var{S}.\n\
\n\
The algorithm represents a heuristic approach to the NP-complete\n\
bandwidth minimization problem. The implementation is based in the\n\
descriptions found in\n\
\n\
E. Cuthill, J. McKee. @cite{Reducing the Bandwidth of Sparse Symmetric\n\
Matrices}. Proceedings of the 24th ACM National Conference, 157--172\n\
1969, Brandon Press, New Jersey.\n\
\n\
A. George, J.W.H. Liu. @cite{Computer Solution of Large Sparse\n\
Positive Definite Systems}, Prentice Hall Series in Computational\n\
Mathematics, ISBN 0-13-165274-5, 1981.\n\
\n\
@seealso{colperm, colamd, symamd}\n\
@end deftypefn") |