SRC/slansy.f(3)            Library Functions Manual            SRC/slansy.f(3)

NAME
       SRC/slansy.f

SYNOPSIS
   Functions/Subroutines
       real function slansy (norm, uplo, n, a, lda, work)
           SLANSY returns the value of the 1-norm, or the Frobenius norm, or
           the infinity norm, or the element of largest absolute value of a
           real symmetric matrix.

Function/Subroutine Documentation
   real function slansy (character norm, character uplo, integer n, real,
       dimension( lda, * ) a, integer lda, real, dimension( * ) work)
       SLANSY returns the value of the 1-norm, or the Frobenius norm, or the
       infinity norm, or the element of largest absolute value of a real
       symmetric matrix.

       Purpose:


            SLANSY  returns the value of the one norm,  or the Frobenius norm, or
            the  infinity norm,  or the  element of  largest absolute value  of a
            real symmetric matrix A.

       Returns
           SLANSY

               SLANSY = ( 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 consistent matrix norm.

       Parameters
           NORM

                     NORM is CHARACTER*1
                     Specifies the value to be returned in SLANSY as described
                     above.

           UPLO

                     UPLO is CHARACTER*1
                     Specifies whether the upper or lower triangular part of the
                     symmetric matrix A is to be referenced.
                     = 'U':  Upper triangular part of A is referenced
                     = 'L':  Lower triangular part of A is referenced

           N

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

           A

                     A is REAL array, dimension (LDA,N)
                     The symmetric 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.

           LDA

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

           WORK

                     WORK is REAL array, dimension (MAX(1,LWORK)),
                     where LWORK >= N when NORM = 'I' or '1' or 'O'; otherwise,
                     WORK is not referenced.

       Author
           Univ. of Tennessee

           Univ. of California Berkeley

           Univ. of Colorado Denver

           NAG Ltd.

       Definition at line 121 of file slansy.f.

Author
       Generated automatically by Doxygen for LAPACK from the source code.

LAPACK                          Version 3.12.0                 SRC/slansy.f(3)