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ZLAPLL(1) LAPACK auxiliary routine (version 3.2) ZLAPLL(1)

NAME

ZLAPLL - two column vectors X and Y, let A = ( X Y )

SYNOPSIS

N, X, INCX, Y, INCY, SSMIN )

INTEGER INCX, INCY, N DOUBLE PRECISION SSMIN COMPLEX*16 X( * ), Y( * )

PURPOSE

Given two column vectors X and Y, let 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

The length of the vectors X and Y.
On entry, X contains the N-vector X. On exit, X is overwritten.
The increment between successive elements of X. INCX > 0.
On entry, Y contains the N-vector Y. On exit, Y is overwritten.
The increment between successive elements of Y. INCY > 0.
The smallest singular value of the N-by-2 matrix A = ( X Y ).
November 2008 LAPACK auxiliary routine (version 3.2)