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Livre :
Expressions régulières,
Syntaxe et mise en oeuvre :

ISBN : 978-2-7460-9712-4
EAN : 9782746097124
(Editions ENI)

GNU/Linux	CentOS 4.8	i386
	slange(l)

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SLANGE

NAME
SYNOPSIS
PURPOSE
DESCRIPTION
ARGUMENTS

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NAME

SLANGE - 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 matrix A

SYNOPSIS

	REAL FUNCTION		SLANGE( NORM, M, N, A, LDA, WORK )
	CHARACTER		NORM
	INTEGER		LDA, M, N
	REAL		A( LDA, * ), WORK( * )

PURPOSE

SLANGE 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 matrix A.

DESCRIPTION

SLANGE returns the value

SLANGE = ( 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 SLANGE as described above.

M (input) INTEGER

The number of rows of the matrix A. M >= 0. When M = 0, SLANGE is set to zero.

N (input) INTEGER

The number of columns of the matrix A. N >= 0. When N = 0, SLANGE is set to zero.

A (input) REAL array, dimension (LDA,N)

The m by n matrix A.

LDA (input) INTEGER

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

WORK (workspace) REAL array, dimension (LWORK),

where LWORK >= M when NORM = ’I’; otherwise, WORK is not referenced.

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slange(l)