Re: Problem of polyfit

[Paul Kienzle]

On Oct 7, 2005, at 7:36 AM, Tetsuro KURITA wrote:

> On 2005/10/07, at 17:32, Fredrik Lingvall wrote:
>
> > Can you post the output of  norm( inv(X'*X)*X'*y - (X'*X)\X'*y )?
>
> The result is as follows.
>
> octave> norm(inv(X'*X)*(X'*y) - (X'*X)\(X'*y))
> warning: matrix singular to machine precision, rcond = 3.02246e-112
> warning: attempting to find minimum norm solution
> ans = 50.504
>
> When calculating (X'*X)\(X'*y), warning message raise.

I get warnings for both:

  warning: inverse: matrix singular to machine precision, rcond = 
3.02246e-112
  warning: matrix singular to machine precision, rcond = 3.02246e-112

The norm is the same.

OS X 10.3 octave 2.1.71 HPC build.

- Paul



-------------------------------------------------------------
Octave is freely available under the terms of the GNU GPL.

Octave's home on the web:  http://www.octave.org
How to fund new projects:  http://www.octave.org/funding.html
Subscription information:  http://www.octave.org/archive.html
-------------------------------------------------------------