Developer Reference for Intel® oneAPI Math Kernel Library for Fortran

ID 766686
Date 6/24/2024
Public

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?la_hercond_x

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

Syntax

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

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

Include Files

  • mkl.fi

Description

The function computes the infinity norm condition number of

op(A) * diag(x)

where the x is a COMPLEX vector for cla_hercond_x and a DOUBLE COMPLEX vector for zla_hercond_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_hercond_c

DOUBLE COMPLEX for zla_hercond_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. ldamax(1,n).

af

COMPLEX for cla_hercond_c

DOUBLE COMPLEX for zla_hercond_c

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

ldaf

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

ipiv

INTEGER.

Array with DIMENSIONn. Details of the interchanges and the block structure of D as determined by ?hetrf.

x

COMPLEX for cla_hercond_c

DOUBLE COMPLEX for zla_hercond_c

Array x with DIMENSIONn. The vector x in the formula

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

work

COMPLEX for cla_hercond_c

DOUBLE COMPLEX for zla_hercond_c

Array DIMENSION 2*n. Workspace.

rwork

REAL for cla_hercond_c

DOUBLE PRECISION for zla_hercond_c

Array DIMENSIONn. Workspace.

Output Parameters

info

INTEGER.

If info = 0, the execution is successful.

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

See Also