?la_syrcond_x

Computes the infinity norm condition number of op(A)*diag(x) for symmetric indefinite matrices.

Syntax

FORTRAN 77:

call cla_syrcond_x( uplo, n, a, lda, af, ldaf, ipiv, x, info, work, rwork )

call zla_syrcond_x( uplo, n, a, lda, af, ldaf, ipiv, x, info, work, rwork )

Include Files

  • Fortran: mkl.fi
  • C: mkl.h

Description

The function computes the infinity norm condition number of

op(A) * diag(x)

where the x is a COMPLEX vector for cla_syrcond_x and a DOUBLE COMPLEX vector for zla_syrcond_x.

Input Parameters

uplo

CHARACTER*1. Must be 'U' or 'L'.

Specifies the triangle of A to store:

If uplo = 'U', the upper triangle of A is stored,

If uplo = 'L', the lower triangle of A is stored.

n

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

a

COMPLEX for cla_syrcond_c

DOUBLE COMPLEX for zla_syrcond_c

Array, DIMENSION (lda, *). On entry, the n-by-n matrix A. The second dimension of a must be at least max(1,n).

lda

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

af

COMPLEX for cla_syrcond_c

DOUBLE COMPLEX for zla_syrcond_c

Array, DIMENSION (ldaf, *). The block diagonal matrix D and the multipliers used to obtain the factor U or L as computed by ?sytrf. The second dimension of af must be at least max(1,n).

ldaf

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

ipiv

INTEGER.

Array with DIMENSION n. Details of the interchanges and the block structure of D as determined by ?sytrf.

x

COMPLEX for cla_syrcond_c

DOUBLE COMPLEX for zla_syrcond_c

Array x with DIMENSION n. The vector x in the formula

op(A) * inv(diag(x)).

work

COMPLEX for cla_syrcond_c

DOUBLE COMPLEX for zla_syrcond_c

Array DIMENSION 2*n. Workspace.

rwork

REAL for cla_syrcond_c

DOUBLE PRECISION for zla_syrcond_c

Array DIMENSION n. Workspace.

Output Parameters

info

INTEGER.

If info = 0, the execution is successful.

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

For more complete information about compiler optimizations, see our Optimization Notice.