Matrix RILU Relax Factor#

Matrix RILU relax factor = <float>

Description / Usage#

This optional card provides a relaxation factor to Aztec to be used in conjunction with preconditioners based on RILU(k,ω) approximate factorization. The input parameter <float> is defined as


fac, a floating point number ( fac ≥ 0 ) that specifies a relaxation factor.

If the Matrix RILU relax factor card is omitted, the default is 1.


Following is a sample card:

Matrix RILU relax factor = 0.5

Technical Discussion#

Some limiting values for fac provide specific behavior:

  • for a value of zero, the ILU(k) is obtained

  • for a value of one, the MILU(k) is obtained.

The value of k is set by the Matrix graph fillin card.