dlapll.f(3) LAPACK dlapll.f(3)
NAME
dlapll.f -
SYNOPSIS
Functions/Subroutines
subroutine dlapll (N, X, INCX, Y, INCY, SSMIN)
DLAPLL measures the linear dependence of two vectors.
Function/Subroutine Documentation
subroutine dlapll (integerN, double precision, dimension( * )X, integerINCX, double precision, dimension( * )Y, integerINCY, double
precisionSSMIN)
DLAPLL measures the linear dependence of two vectors.
Purpose:
Given two column vectors X and Y, let
A = ( X Y ).
The subroutine first computes the QR factorization of A = Q*R,
and then computes the SVD of the 2-by-2 upper triangular matrix R.
The smaller singular value of R is returned in SSMIN, which is used
as the measurement of the linear dependency of the vectors X and Y.
Parameters:
N
N is INTEGER
The length of the vectors X and Y.
X
X is DOUBLE PRECISION array,
dimension (1+(N-1)*INCX)
On entry, X contains the N-vector X.
On exit, X is overwritten.
INCX
INCX is INTEGER
The increment between successive elements of X. INCX > 0.
Y
Y is DOUBLE PRECISION array,
dimension (1+(N-1)*INCY)
On entry, Y contains the N-vector Y.
On exit, Y is overwritten.
INCY
INCY is INTEGER
The increment between successive elements of Y. INCY > 0.
SSMIN
SSMIN is DOUBLE PRECISION
The smallest singular value of the N-by-2 matrix A = ( X Y ).
Author:
Univ. of Tennessee
Univ. of California Berkeley
Univ. of Colorado Denver
NAG Ltd.
Date:
September 2012
Definition at line 103 of file dlapll.f.
Author
Generated automatically by Doxygen for LAPACK from the source code.
Version 3.4.2 Tue Sep 25 2012 dlapll.f(3)
