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NAME
     dlansy - 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 real symmetric matrix A

SYNOPSIS
     DOUBLE PRECISION FUNCTION DLANSY( NORM,  UPLO,  N,  A,  LDA,
               WORK )

     CHARACTER NORM, UPLO

     INTEGER LDA, N

     DOUBLE PRECISION A( LDA, * ), WORK( * )



     #include <sunperf.h>

     double dlansy(char norm, char uplo, int n, double  *da,  int
               lda) ;

PURPOSE
     DLANSY  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.


DESCRIPTION
     DLANSY returns the value

        DLANSY = ( 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  DLANSY  as
               described above.

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

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

     A         (input) DOUBLE PRECISION array, dimension (LDA,N)
               The symmetric matrix A.  If UPLO = 'U', the  lead-
               ing 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 refer-
               enced.  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  tri-
               angular part of A is not referenced.

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

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

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