
dlantr.f(3) LAPACK dlantr.f(3)
NAME
dlantr.f 
SYNOPSIS
Functions/Subroutines
DOUBLE PRECISION function dlantr (NORM, UPLO, DIAG, M, N, A, LDA, WORK)
DLANTR returns the value of the 1norm, or the Frobenius norm, or the infinity norm,
or the element of largest absolute value of a trapezoidal or triangular matrix.
Function/Subroutine Documentation
DOUBLE PRECISION function dlantr (characterNORM, characterUPLO, characterDIAG, integerM,
integerN, double precision, dimension( lda, * )A, integerLDA, double precision, dimension(
* )WORK)
DLANTR returns the value of the 1norm, or the Frobenius norm, or the infinity norm, or
the element of largest absolute value of a trapezoidal or triangular matrix.
Purpose:
DLANTR returns the value of the one norm, or the Frobenius norm, or
the infinity norm, or the element of largest absolute value of a
trapezoidal or triangular matrix A.
Returns:
DLANTR
DLANTR = ( 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 DLANTR as described
above.
UPLO
UPLO is CHARACTER*1
Specifies whether the matrix A is upper or lower trapezoidal.
= 'U': Upper trapezoidal
= 'L': Lower trapezoidal
Note that A is triangular instead of trapezoidal if M = N.
DIAG
DIAG is CHARACTER*1
Specifies whether or not the matrix A has unit diagonal.
= 'N': Nonunit diagonal
= 'U': Unit diagonal
M
M is INTEGER
The number of rows of the matrix A. M >= 0, and if
UPLO = 'U', M <= N. When M = 0, DLANTR is set to zero.
N
N is INTEGER
The number of columns of the matrix A. N >= 0, and if
UPLO = 'L', N <= M. When N = 0, DLANTR is set to zero.
A
A is DOUBLE PRECISION array, dimension (LDA,N)
The trapezoidal matrix A (A is triangular if M = N).
If UPLO = 'U', the leading m by n upper trapezoidal part of
the array A contains the upper trapezoidal matrix, and the
strictly lower triangular part of A is not referenced.
If UPLO = 'L', the leading m by n lower trapezoidal part of
the array A contains the lower trapezoidal matrix, and the
strictly upper triangular part of A is not referenced. Note
that when DIAG = 'U', the diagonal elements of A are not
referenced and are assumed to be one.
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 141 of file dlantr.f.
Author
Generated automatically by Doxygen for LAPACK from the source code.
Version 3.4.2 Tue Sep 25 2012 dlantr.f(3) 
