# 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

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).

Tue Nov 14 2017 Version 3.8.0 LAPACK