dlapll.f man page

dlapll.f —

Synopsis

Functions/Subroutines

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

Function/Subroutine Documentation

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.

Date:

December 2016

Definition at line 104 of file dlapll.f.

Author

Generated automatically by Doxygen for LAPACK from the source code.

Referenced By

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

Sat Jun 24 2017 Version 3.7.1 LAPACK