CLANGE(l) ) CLANGE(l)NAME
CLANGE - return the value of the one norm, or the Frobenius norm, or
the infinity norm, or the element of largest absolute value of a com‐
plex matrix A
SYNOPSIS
REAL FUNCTION CLANGE( NORM, M, N, A, LDA, WORK )
CHARACTER NORM
INTEGER LDA, M, N
REAL WORK( * )
COMPLEX A( LDA, * )
PURPOSE
CLANGE returns the value of the one norm, or the Frobenius norm, or the
infinity norm, or the element of largest absolute value of a complex
matrix A.
DESCRIPTION
CLANGE returns the value
CLANGE = ( 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 CLANGE as described
above.
M (input) INTEGER
The number of rows of the matrix A. M >= 0. When M = 0,
CLANGE is set to zero.
N (input) INTEGER
The number of columns of the matrix A. N >= 0. When N = 0,
CLANGE is set to zero.
A (input) COMPLEX 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 refer‐
enced.
LAPACK version 3.0 15 June 2000 CLANGE(l)
