dlange.f man page

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 (characterNORM, integerM, integerN, double precision, dimension( lda, * )A, integerLDA, 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.

Date:

September 2012

Definition at line 115 of file dlange.f.

Author

Generated automatically by Doxygen for LAPACK from the source code.

Referenced By

dlange(3) is an alias of dlange.f(3).

Sat Nov 16 2013 Version 3.4.2 LAPACK