Provided by: liblapack-doc_3.12.0-3build1.1_all 
NAME
lapll - lapll: linear dependence of 2 vectors
SYNOPSIS
Functions
subroutine clapll (n, x, incx, y, incy, ssmin)
CLAPLL measures the linear dependence of two vectors.
subroutine dlapll (n, x, incx, y, incy, ssmin)
DLAPLL measures the linear dependence of two vectors.
subroutine slapll (n, x, incx, y, incy, ssmin)
SLAPLL measures the linear dependence of two vectors.
subroutine zlapll (n, x, incx, y, incy, ssmin)
ZLAPLL measures the linear dependence of two vectors.
Detailed Description
Function Documentation
subroutine clapll (integer n, complex, dimension( * ) x, integer incx, complex, dimension( * )
y, integer incy, real ssmin)
CLAPLL 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 COMPLEX 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 COMPLEX 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 REAL
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.
subroutine dlapll (integer n, double precision, dimension( * ) x, integer incx, double
precision, dimension( * ) y, integer incy, double precision ssmin)
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.
subroutine slapll (integer n, real, dimension( * ) x, integer incx, real, dimension( * ) y,
integer incy, real ssmin)
SLAPLL 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 REAL 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 REAL 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 REAL
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.
subroutine zlapll (integer n, complex*16, dimension( * ) x, integer incx, complex*16,
dimension( * ) y, integer incy, double precision ssmin)
ZLAPLL 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 COMPLEX*16 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 COMPLEX*16 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.
Author
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