Re: Problem of polyfit

[Tetsuro KURITA]

On 2005/10/07, at 13:05, Dmitri A. Sergatskov wrote:

> You would get a very good fit if you normalize your data

Thanks.
It seems that my opinion was wrong.
I feel embarrassed about making much ado.

Why normailing data is requred.

But there was a person who meets same trouble to mine.

http://www.octave.org/octave-lists/archive/help-octave.1999/ 
msg01007.html
http://www.octave.org/octave-lists/archive/help-octave.1999/ 
msg01008.html

I hope polyfit will be improved for less hustle.

Also following two equations do not return same results, when  
calculating data I posted.

  p = inv(X'*X)*(X'*y);

  p = (X'*X)\(X'*y);

In the case of data I posted, first equation give better results. It  
looks that the operator "\" have a certain limitation. What is that ?

=======================================================
 Tetsuro KURITA
  E-mail: address@hidden
=======================================================



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