# ?lanhp

Returns the value of the 1-norm, or the Frobenius norm, or the infinity norm, or the element of largest absolute value of a complex Hermitian matrix supplied in packed form.

## Syntax

val = clanhp( norm, uplo, n, ap, work )

val = zlanhp( norm, uplo, n, ap, work )

## Include Files

• Fortran: mkl.fi
• C: mkl.h

## Description

The function ?lanhp returns the value of the 1-norm, or the Frobenius norm, or the infinity norm, or the element of largest absolute value of a complex Hermitian matrix A, supplied in packed form.

## Input Parameters

norm

CHARACTER*1. Specifies the value to be returned by the routine:

= 'M' or 'm': val = max(abs(Aij)), largest absolute value of the matrix A.

= '1' or 'O' or 'o': val = norm1(A), 1-norm of the matrix A (maximum column sum),

= 'I' or 'i': val = normI(A), infinity norm of the matrix A (maximum row sum),

= 'F', 'f', 'E' or 'e': val = normF(A), Frobenius norm of the matrix A (square root of sum of squares).

uplo

CHARACTER*1.

Specifies whether the upper or lower triangular part of the Hermitian matrix A is supplied.

If `uplo = 'U'`: Upper triangular part of A is supplied

If `uplo = 'L'`: Lower triangular part of A is supplied.

n

INTEGER. The order of the matrix A.

`n ≥ 0`. When `n = 0`, ?lanhp is set to zero.

ap

COMPLEX for clanhp.

DOUBLE COMPLEX for zlanhp.

Array, DIMENSION (`n(n+1)/2`). The upper or lower triangle of the Hermitian matrix A, packed columnwise in a linear array. The j-th column of A is stored in the array ap as follows:

if `uplo = 'U'`, `ap(i + (j-1)j/2) = A(i,j)` for `1 ≤ i ≤ j`;

if `uplo = 'L'`, `ap(i + (j-1)(2n-j)/2) = A(i,j)` for `j ≤ i ≤ n`.

work

REAL for clanhp.

DOUBLE PRECISION for zlanhp.

Workspace array, DIMENSION `(max(1,lwork))`, where

`lwork ≥ n` when `norm = 'I'` or '1' or 'O'; otherwise, work is not referenced.

## Output Parameters

val

REAL for clanhp.

DOUBLE PRECISION for zlanhp.

Value returned by the function.

Pour de plus amples informations sur les optimisations de compilation, consultez notre Avertissement concernant les optimisations.