dlapll.f(3)

dlapll.f3

Usage

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.

Definition at line 101 of file dlapll.f.

Releases

4 releases since Debian 7 (Wheezy); the text changed 3 times.

  1. 7
  2. 8
  3. 9
  4. Arch

Author

Generated automatically by Doxygen for LAPACK from the source code.

From lapack-doc 3.12.1-2 in Arch Linux 2026-11-01. Parsed by carta from the page's man source.