zgerfs

TRANS, N, NRHS, A, LDA, AF, LDAF, IPIV, B, LDB, X, LDX, FERR, BERR, WORK, RWORK, INFO )

CHARACTER TRANS

INTEGER INFO, LDA, LDAF, LDB, LDX, N, NRHS

INTEGER IPIV( * )

DOUBLE PRECISION BERR( * ), FERR( * ), RWORK( * )

COMPLEX*16 A( LDA, * ), AF( LDAF, * ), B( LDB, * ), WORK( * ), X( LDX, * )

Specifies the form of the system of equations:
= 'N': A * X = B (No transpose)
= 'T': A**T * X = B (Transpose)
= 'C': A**H * X = B (Conjugate transpose)

The order of the matrix A. N >= 0.

The number of right hand sides, i.e., the number of columns of the matrices B and X. NRHS >= 0.

The original N-by-N matrix A.

The leading dimension of the array A. LDA >= max(1,N).

The factors L and U from the factorization A = P*L*U as computed by ZGETRF.

The leading dimension of the array AF. LDAF >= max(1,N).

The pivot indices from ZGETRF; for 1<=i<=N, row i of the matrix was interchanged with row IPIV(i).

The right hand side matrix B.

The leading dimension of the array B. LDB >= max(1,N).

On entry, the solution matrix X, as computed by ZGETRS. On exit, the improved solution matrix X.

The leading dimension of the array X. LDX >= max(1,N).

The estimated forward error bound for each solution vector X(j) (the j-th column of the solution matrix X). If XTRUE is the true solution corresponding to X(j), FERR(j) is an estimated upper bound for the magnitude of the largest element in (X(j) - XTRUE) divided by the magnitude of the largest element in X(j). The estimate is as reliable as the estimate for RCOND, and is almost always a slight overestimate of the true error.

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).

= 0: successful exit
< 0: if INFO = -i, the i-th argument had an illegal value