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C++ API

: p = symrcm (S)

Return the symmetric reverse Cuthill-McKee permutation of S.

p is a permutation vector such that S(p, p) tends to have its diagonal elements closer to the diagonal than S. This is a good preordering for LU or Cholesky factorization of matrices that come from “long, skinny” problems. It works for both symmetric and asymmetric S.

The algorithm represents a heuristic approach to the NP-complete bandwidth minimization problem. The implementation is based in the descriptions found in

E. Cuthill, J. McKee. Reducing the Bandwidth of Sparse Symmetric Matrices. Proceedings of the 24th ACM National Conference, 157–172 1969, Brandon Press, New Jersey.

A. George, J.W.H. Liu. Computer Solution of Large Sparse Positive Definite Systems, Prentice Hall Series in Computational Mathematics, ISBN 0-13-165274-5, 1981.

See also: colperm, colamd, symamd.

Package: octave