?la_gercond_x

Syntax

FORTRAN 77:

call cla_gercond_x( trans, n, a, lda, af, ldaf, ipiv, x, info, work, rwork )

call zla_gercond_x( trans, n, a, lda, af, ldaf, ipiv, x, info, work, rwork )

Include Files

The FORTRAN 77 interfaces are specified in the mkl_lapack.fi and mkl_lapack.h include files.

Description

The function computes the infinity norm condition number of

op(A) * diag(x)

where the x is a COMPLEX vector for cla_gercond_x and a DOUBLE COMPLEX vector for zla_gercond_x.

Input Parameters

trans

CHARACTER*1. Must be 'N' or 'T' or 'C'.

Specifies the form of the system of equations:

If trans = 'N', the system has the form A*X = B (No transpose)

If trans = 'T', the system has the form A^T*X = B (Transpose)

If trans = 'C', the system has the form A^H*X = B (Conjugate Transpose = Transpose)

n

INTEGER. The number of linear equations, that is, the order of the matrix A; n ≥ 0.

a, af, x, work

COMPLEX for cla_gercond_x

DOUBLE COMPLEX for zla_gercond_x

Arrays:

a(lda,*) contains the original general n-by-n matrix A.

af(ldaf,*) contains the factors L and U from the factorization A=P*L*U as returned by ?getrf.

x, DIMENSION n. The vector x in the formula op(A) * diag(x).

work is a workspace array of DIMENSION (2*n).

The second dimension of a and af must be at least max(1, n).

lda

INTEGER. The leading dimension of the array a. lda ≥ max(1,n).

ldaf

INTEGER. The leading dimension of af. ldaf ≥ max(1,n).

ipiv

INTEGER.

Array with DIMENSION n. The pivot indices from the factorization A = P*L*U as computed by ?getrf. Row i of the matrix was interchanged with row ipiv(i).

rwork

REAL for cla_gercond_x

DOUBLE PRECISION for zla_gercond_x

Array rwork with DIMENSION n is a workspace.

Output Parameters

info

INTEGER.

If info = 0, the execution is successful.

If i > 0, the i-th parameter is invalid.