LANHE - 5.2 English - 68552

AOCL API Guide (68552)

Document ID
68552
Release Date
2025-12-29
Version
5.2 English
template<typename T, typename Ta>
Ta lanhe(char *norm, char *uplo, integer *n, T *a, integer *lda, Ta *work)#

LANHE 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.

Purpose:

   LANHE  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.
* \b Returns LANHE

      CLANHE = ( fla_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  fla_max(abs(A(i,j)))  is not a consistent matrix norm.
Parameters:
  • NORM[in]

    NORM is CHARACTER*1

    Specifies the value to be returned in CLANHE as described above.

  • UPLO[in]

    UPLO is CHARACTER*1

    Specifies whether the upper or lower triangular part of the hermitian matrix A is to be referenced.

    = ‘U’: Upper triangular part of A is referenced

    = ‘L’: Lower triangular part of A is referenced

  • N[in]

    N is INTEGER

    The order of the matrix A. N >= 0. When N = 0, CLANHE is set to zero.

  • A[in]

    A is COMPLEX array, dimension (LDA,N)

    The hermitian matrix A. If UPLO = ‘U’, the leading n by n upper triangular part of A contains the upper triangular part of the matrix A, and the strictly lower triangular part of A is not referenced. If UPLO = ‘L’, the leading n by n lower triangular part of A contains the lower triangular part of the matrix A, and the strictly upper triangular part of A is not referenced. Note that the imaginary parts of the diagonal elements need not be set and are assumed to be zero.

  • LDA[in]

    LDA is INTEGER

    The leading dimension of the array A. LDA >= fla_max(N,1).

  • WORK[out]

    WORK is REAL array, dimension (MAX(1,LWORK)),

    where LWORK >= N when NORM = ‘I’ or ‘1’ or ‘O’; otherwise, WORK is not referenced.

Returns:

Returns value of the norm.