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

Chapter 13 Sparse Linear Equations 925
One-call usage DSLELU
purpose of forming columns with identical structure to
increase the efficiency of the factorization. If
maxzer = 0, no additional fill is allowed. 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
= 10 could be tried but maxzer = 0 is perfectly
acceptable. Using values greater than 50 probably
increases the factorization time.
pvttol Not used in this case.
msglvl Message level for printable output. Options:
msglvl ≤ 0 Suppress all output.
msglvl = 1 Error messages and summary
statistics.
msglvl = 2 More complete statistics.
msglvl = 3 First stage of debugging output.
msglvl = 4 Complete debugging output.
output Fortran logical unit number to which all printable
output is written.
nrhs Number of right-hand sides.
ldrhs The leading dimension of array rhs as declared in the
calling program unit, with ldrhs ≥ neqns.
colstr colstr(j) gives the index in rowind of the first nonzero
in column j of the matrix. All of the nonzeros for
column j are found, in ascending order, in
rowind(colstr(j)), rowind(colstr(j)+1), ...,
rowind(colstr(j+1)−1).
colstr(neqns+1) must be set to one greater than the
total number of nonzeros, nnzero, in the matrix.
rowind List of row indices for all nonzeros, in ascending order
within each column, in the matrix A.
value List of values corresponding in position to the indices
in rowind.
Updated rhs On input, rhs contains the nrhs right-hand sides. On
output, rhs has been overwritten with the computed
solutions.
Output ier Status response: