SLAPLL(l) ) SLAPLL(l)NAME
SLAPLL - two column vectors X and Y, let A = ( X Y )
SYNOPSIS
SUBROUTINE SLAPLL( N, X, INCX, Y, INCY, SSMIN )
INTEGER INCX, INCY, N
REAL SSMIN
REAL X( * ), Y( * )
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.
ARGUMENTS
N (input) INTEGER
The length of the vectors X and Y.
X (input/output) REAL array,
dimension (1+(N-1)*INCX) On entry, X contains the N-vector X.
On exit, X is overwritten.
INCX (input) INTEGER
The increment between successive elements of X. INCX > 0.
Y (input/output) REAL array,
dimension (1+(N-1)*INCY) On entry, Y contains the N-vector Y.
On exit, Y is overwritten.
INCY (input) INTEGER
The increment between successive elements of Y. INCY > 0.
SSMIN (output) REAL
The smallest singular value of the N-by-2 matrix A = ( X Y ).
LAPACK version 3.0 15 June 2000 SLAPLL(l)