
dlansy.f(3) LAPACK dlansy.f(3)
NAME
dlansy.f 
SYNOPSIS
Functions/Subroutines
DOUBLE PRECISION function dlansy (NORM, UPLO, N, A, LDA, WORK)
DLANSY returns the value of the 1norm, or the Frobenius norm, or the infinity norm,
or the element of largest absolute value of a real symmetric matrix.
Function/Subroutine Documentation
DOUBLE PRECISION function dlansy (characterNORM, characterUPLO, integerN, double precision,
dimension( lda, * )A, integerLDA, double precision, dimension( * )WORK)
DLANSY returns the value of the 1norm, or the Frobenius norm, or the infinity norm, or
the element of largest absolute value of a real symmetric matrix.
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.
Returns:
DLANSY
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 consistent matrix norm.
Parameters:
NORM
NORM is CHARACTER*1
Specifies the value to be returned in DLANSY 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, DLANSY is
set to zero.
A
A is DOUBLE PRECISION 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 DOUBLE PRECISION 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.
Date:
September 2012
Definition at line 123 of file dlansy.f.
Author
Generated automatically by Doxygen for LAPACK from the source code.
Version 3.4.2 Tue Sep 25 2012 dlansy.f(3) 
