Matrix Graph Fillin#

Matrix graph fillin = <integer>4.7.10_matrix_factorization_overlap.txt

Description / Usage#

This optional card sets the graph level of fill-in for approximate factorizations used in preconditioner construction for ILU(k), ICC(k) and BILU(k). The input parameter is defined as


k, specifies the graph level of fill-in, k > 0.

If the Matrix graph fillin card is omitted, the default value of k is 0.


Following is a sample card:

Matrix graph fillin = 2

Technical Discussion#

As the level of graph fill-in increases, the accuracy (usefulness) of the preconditioner increases; however, so does memory usage as well as the time required to compute the preconditioner.