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

778 HP MLIB LAPACK User’s Guide
pdgssvx/ pzgssvx, pdgssvx_ABglobal/pzgssvx_ABglobal Solve systems of linear equations
Inputs: A, options->Equil, options->RowPerm,
options->ReplaceTinyPivot, all of
ScalePermstruct, all of LUstruct
Outputs: modified A (possibly row and/or column
scaled and/or permuted), modified LUstruct->Llu
= FACTORED
: The matrix A is already factored.
Inputs: all of ScalePermstruct, all of LUstruct
• Equil (yes_no_t) Specifies whether to equilibrate the
system.
= NO: No equilibration.
= YES: Scaling factors are computed to equilibrate
the system:
diag(R)*A*diag(C)*inv(diag(C))*X = diag(R)*B
Whether or not the system will be equilibrated
depends on the scaling of the matrix A, but if
equilibration is used, A is overwritten by
diag(R)*A*diag(C) and B by diag(R)*B.
• RowPerm (rowperm_t) Specifies how to permute
rows of the matrix A.
= NATURAL: Use the natural ordering.
= LargeDiag: Use the Duff/Koster algorithm to
permute rows of the original matrix to make the
diagonal large relative to the off-diagonal.
= MY_PERMR: Use the ordering given in
ScalePermstruct->perm_r input by the user.
• ColPerm (colperm_t) specifies what type of column
permutation to use to reduce fill.