zlapll.f man page

zlapll.f —

Synopsis

Functions/Subroutines

subroutine zlapll (N, X, INCX, Y, INCY, SSMIN)
ZLAPLL measures the linear dependence of two vectors.

Function/Subroutine Documentation

subroutine zlapll (integerN, complex*16, dimension( * )X, integerINCX, complex*16, dimension( * )Y, integerINCY, double precisionSSMIN)

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.

Date:

September 2012

Definition at line 101 of file zlapll.f.

Author

Generated automatically by Doxygen for LAPACK from the source code.

Referenced By

zlapll(3) is an alias of zlapll.f(3).

Sat Nov 16 2013 Version 3.4.2 LAPACK