HP MLIB User's Guide Vol. 2 7th Ed.

938 HP MLIB User’s Guide
DSLEOR Reordering and symbolic factorization
INTEGER*8 maxzer, ier
REAL*8 global(150)
CALL CSLEOR(maxzer, global, ier)
INTEGER*8 maxzer, ier
REAL*8 global(150)
CALL ZSLEOR(maxzer, global, ier)
Input maxzer Supernodal relaxation parameter; maxzer ≥ 0.
If maxzer > 0, the package allows additional fill for the
purpose of forming columns with identical structure to
increase the efficiency of the factorization.
If maxzer = 0 no additional fill is allowed. Performance
studies indicate that a value of 20 to 25 optimize the
factorization execution time with a reduction of 5 to
10%. Because of the additional fill, the solution
execution time may increase by 1 to 2%.
If many solution vectors are to be computed for each
factorization, it is suggested that maxzer = 0 be used.
If only a few solution vectors are to be computed
maxzer = 25 could be tried but maxzer = 0 is perfectly
acceptable. Using values greater than 100 probably
increase the factorization time.
Updated global Global communications array for this problem. This
array must be passed, untouched by the user, to
successive subroutines in this package.
Output ier Status response:
ier = 0 Normal return.
ier = −200 Incorrect processing path; structure
input not completed or value input
subroutines already called.
ier = −201 Error in dynamic storage allocation.