# ?la_porcond_c

Computes the infinity norm condition number of op(A)*inv(diag(c)) for Hermitian positive-definite matrices.

## Syntax

call cla_porcond_c( uplo, n, a, lda, af, ldaf, c, capply, info, work, rwork )

call zla_porcond_c( uplo, n, a, lda, af, ldaf, c, capply, info, work, rwork )

• mkl.fi

## Description

The function computes the infinity norm condition number of

`op(A) * inv(diag(c))`

where the c is a REAL vector for cla_porcond_c and a DOUBLE PRECISION vector for zla_porcond_c.

## 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_porcond_c

DOUBLE COMPLEX for zla_porcond_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_porcond_c

DOUBLE COMPLEX for zla_porcond_c

Array, DIMENSION `(ldaf, *)`. The triangular factor L or U from the Cholesky factorization

`A = UH*U` or `A = L*LH`,

as computed by ?potrf.

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)`.

c

REAL for cla_porcond_c

DOUBLE PRECISION for zla_porcond_c

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

`op(A) * inv(diag(c))`.

capply

LOGICAL. If .TRUE., then the function uses the vector c from the formula

`op(A) * inv(diag(c))`.

work

COMPLEX for cla_porcond_c

DOUBLE COMPLEX for zla_porcond_c

Array DIMENSION 2*n. Workspace.

rwork

REAL for cla_porcond_c

DOUBLE PRECISION for zla_porcond_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.