SRC/dlange.f(3) | Library Functions Manual | SRC/dlange.f(3) |
NAME
SRC/dlange.f
SYNOPSIS
Functions/Subroutines
double precision function dlange (norm, m, n, a, lda, work)
DLANGE returns the value of the 1-norm, Frobenius norm, infinity-norm,
or the largest absolute value of any element of a general rectangular
matrix.
Function/Subroutine Documentation
double precision function dlange (character norm, integer m, integer n, double precision, dimension( lda, * ) a, integer lda, double precision, dimension( * ) work)
DLANGE returns the value of the 1-norm, Frobenius norm, infinity-norm, or the largest absolute value of any element of a general rectangular matrix.
Purpose:
DLANGE 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.
Returns
DLANGE
DLANGE = ( 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 DLANGE as described above.
M
M is INTEGER The number of rows of the matrix A. M >= 0. When M = 0, DLANGE is set to zero.
N
N is INTEGER The number of columns of the matrix A. N >= 0. When N = 0, DLANGE is set to zero.
A
A is DOUBLE PRECISION array, dimension (LDA,N) The m by n matrix A.
LDA
LDA is INTEGER The leading dimension of the array A. LDA >= max(M,1).
WORK
WORK is DOUBLE PRECISION array, dimension (MAX(1,LWORK)), where LWORK >= M when NORM = 'I'; otherwise, WORK is not referenced.
Author
Univ. of Tennessee
Univ. of California Berkeley
Univ. of Colorado Denver
NAG Ltd.
Definition at line 113 of file dlange.f.
Author
Generated automatically by Doxygen for LAPACK from the source code.
Version 3.12.0 | LAPACK |