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

Chapter 11 Introduction to Distributed SuperLU 767
Improve the computed solutions to systems of distributed linear equations pdgsrfs/pzgsrfs
or pzgstrf for the possibly scaled and permuted matrix
A.
ScalePermstruct
(input)
(global) The data structure to store the scaling and
permutation vectors describing the trasformations
performed to the matrix A.
grid
(input)
The 2D process mesh. It contains the MPI
communicator, the number of process rows (NPROW),
the number of process columns (NPCOL), and my
process rank, It is an input argument to all the parallel
routines. Grid can be initialized by subroutine
SUPERLU_GRINDINIT.
B
(input)
(local) The m_loc-by-NRHS right-hand side matrix of the
possibly equilibrated system.
ldb
(input)(local)
The leading dimension of matrix B.
X
(input/output)
(local)
On entry, the solution matrix X, as computed by
pdgstrs or pzgstrs. On exit, the improved solution
matrix Y.
ldx
(input)(local)
The leading dimension of matrix X.
nrhs
(input)
The number of right-hand sides.
SOLVEstruct
(output)(global)
Contains the information for the communication
during the solution phase.
berr
(output)
dimension
(nrhs) The componentwise relative backward error of each
solution vector X(j) (i.e., the smallest relative change in
any element of A or B that makes X(j) an exact
solution).