Umfpack

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Umfpack#

This command is used to construct a sparse system of equations which uses the UmfPack solver.

system Umfpack <-lvalueFact $LVALUE>

LVALUE*Nnz is the amount of additional memory set aside for fill in during the matrix solution where Nnz is the number of nonzero entries. By default the LVALUE factor is 10. You only need to experiment with this if you get error messages back about LVALUE being too small.

The number of threads used by this system can be altered by setting the OMP_NUM_THREADS environment variable.

Example#

The following example shows how to construct a Umfpack system

system Umfpack

References#

  1. A column pre-ordering strategy for the unsymmetric-pattern multifrontal method, T. A. Davis, ACM Transactions on Mathematical Software, vol 30, no. 2, June 2004, pp. 165-195.

  2. Algorithm 832: UMFPACK, an unsymmetric-pattern multifrontal method, T. A. Davis, ACM Transactions on Mathematical Software, vol 30, no. 2, June 2004, pp. 196-199.

  3. A combined unifrontal/multifrontal method for unsymmetric sparse matrices, T. A. Davis and I. S. Duff, ACM Transactions on Mathematical Software, vol. 25, no. 1, pp. 1-19, March 1999.

  4. An unsymmetric-pattern multifrontal method for sparse LU factorization, T. A. Davis and I. S. Duff, SIAM Journal on Matrix Analysis and Applications, vol 18, no. 1, pp. 140-158, Jan. 1997.

Code developed by: fmk

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