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# clanhp

```
NAME
CLANHP - return the value of the one norm, or the Frobenius
norm, or the infinity norm, or the element of largest abso-
lute value of a complex hermitian matrix A, supplied in
packed form

SYNOPSIS
REAL FUNCTION CLANHP( NORM, UPLO, N, AP, WORK )

CHARACTER NORM, UPLO

INTEGER   N

REAL      WORK( * )

COMPLEX   AP( * )

PURPOSE
CLANHP  returns the value of the one 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.

DESCRIPTION
CLANHP returns the value

CLANHP = ( max(abs(A(i,j))), NORM = 'M' or 'm'
(
( norm1(A),         NORM = '1', 'O' or 'o'
(
( normI(A),         NORM = 'I' or 'i'
(
( normF(A),         NORM = 'F', 'f', 'E' or 'e'

where  norm1  denotes the  one norm of a matrix (maximum
column sum), normI  denotes the  infinity norm  of a matrix
(maximum row sum) and normF  denotes the  Frobenius norm of
a matrix (square root of sum of squares).  Note that
max(abs(A(i,j)))  is not a  matrix norm.

ARGUMENTS
NORM    (input) CHARACTER*1
Specifies the value to be returned in CLANHP as
described above.

UPLO    (input) CHARACTER*1
Specifies whether the upper or lower triangular part
of the hermitian matrix A is supplied.  = 'U':
Upper triangular part of A is supplied
= 'L':  Lower triangular part of A is supplied

N       (input) INTEGER
The order of the matrix A.  N >= 0.  When N = 0,
CLANHP is set to zero.

AP      (input) COMPLEX 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.  Note that the  imaginary parts of the
diagonal elements need not be set and are assumed to
be zero.

WORK    (workspace) REAL array, dimension (LWORK),
where LWORK >= N when NORM = 'I' or '1' or 'O'; oth-
erwise, WORK is not referenced.
```