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

780 HP MLIB LAPACK User’s Guide

pdgssvx/ pzgssvx, pdgssvx_ABglobal/pzgssvx_ABglobal Solve systems of linear equations

The type of A must be: Stype=SLU_NR_loc for pdgssvx

and pzgssvx and SLU_NC for pdgssvx_ABglobal and

pzgssvx_ABglobal; Dtype=SLU_D for

pdgssvx_ABglobal or Z for pzgssvx_ABglobal;

Mtype=SLU_GE. That is, A is stored in distributed

compressed row format for pdgssvx and pzgssvx, and

in compressed column format (also known as

Herwell-Boeing format) for pdgssvx_ABglobal and

pzgssvx_ABglobal. This routine only handles square A,

however, the LU factorization routines pdgstrf_Aglobal

and pzgstrf_Aglobal can factorize rectangular

matrices. On exit, A may be overwritten by

Pc*Pr*diag(R)*A*diag(C), depending on

ScalePermstruct->DiagScale, options->RowPerm, and

options->ColPerm:

If ScalePermstruct->DiagScale !=NOEQUIL, A is

overwritten by diag(R)*A*diag(C).

If options->RowPerm !=NATURAL, A is further

overwritten by Pr*diag(R)*A*diag(C).

If options->ColPerm !=NATURAL, A is further

overwritten by Pc*Pr*dig(R)*A*diag(C).

If all the above conditions are true, the LU

decomposition is performed on the matrix

Pc*Pr*diag(R)*A*diag(c)*Pc^T.

NOTE A is local for pdgssvx and pzgssvx, and global for pdgssvx_ABglobal and

pzgssvx_ABglobal.

ScalePermstruct

(input/output)

The data structure to store the scaling and

permutation vectors describing the transformations

performed to the matrix A. It contains the following

ﬁelds:

• DiagScale (DiagScale_t) Speciﬁes the form of

equilibration that was done.

= NOEQUIL: No equilibration.