
SLANSY(l) ) SLANSY(l)
NAME
SLANSY  return 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
SYNOPSIS
REAL FUNCTION SLANSY( NORM, UPLO, N, A, LDA, WORK )
CHARACTER NORM, UPLO
INTEGER LDA, N
REAL A( LDA, * ), WORK( * )
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.
DESCRIPTION
SLANSY returns the value
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 matrix
norm.
ARGUMENTS
NORM (input) CHARACTER*1
Specifies the value to be returned in SLANSY as described above.
UPLO (input) 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 (input) INTEGER
The order of the matrix A. N >= 0. When N = 0, SLANSY is set to zero.
A (input) 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 (input) INTEGER
The leading dimension of the array A. LDA >= max(N,1).
WORK (workspace) REAL array, dimension (LWORK),
where LWORK >= N when NORM = 'I' or '1' or 'O'; otherwise, WORK is not referenced.
LAPACK version 3.0 15 June 2000 SLANSY(l) 
