LAPACK  3.5.0 LAPACK: Linear Algebra PACKage
dlange.f File Reference

Go to the source code of this file.

## 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. More...

## 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
 [in] NORM ``` NORM is CHARACTER*1 Specifies the value to be returned in DLANGE as described above.``` [in] M ``` M is INTEGER The number of rows of the matrix A. M >= 0. When M = 0, DLANGE is set to zero.``` [in] N ``` N is INTEGER The number of columns of the matrix A. N >= 0. When N = 0, DLANGE is set to zero.``` [in] A ``` A is DOUBLE PRECISION array, dimension (LDA,N) The m by n matrix A.``` [in] LDA ``` LDA is INTEGER The leading dimension of the array A. LDA >= max(M,1).``` [out] WORK ``` WORK is DOUBLE PRECISION array, dimension (MAX(1,LWORK)), where LWORK >= M when NORM = 'I'; otherwise, WORK is not referenced.```
Date
September 2012

Definition at line 115 of file dlange.f.

Here is the call graph for this function: