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 (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.

Date:

December 2016

Definition at line 102 of file zlapll.f.

Author

Generated automatically by Doxygen for LAPACK from the source code.

Referenced By

The man page zlapll(3) is an alias of zlapll.f(3).

Tue Nov 14 2017 Version 3.8.0 LAPACK