Matti Overmark wrote:
> I have fitted a 3 rd degree curve to a sample (least square method), and
> I want to compare this particular R2 with that of
> a (similarily) fitted 2 degree polynom.
I can assure you that the 3rd degree polynomial will fit as well or
better than the 2nd degree polynomial, as measured by R-squared. If you
want a statistical test to test the hypothesis that the 3rd degree model
yields a significantly better fit compared to the second degree model,
then you should do an "extra-sums-of-squares" test, as explained in the
fine textbook by Draper and Smith "Applied Regression Analysis".
> I want to "see" which of the two models is the best.
> Any suggestion of a good book?
A plot would work just fine, if you want to "see" how the models fit.
--
Paige Miller
Eastman Kodak Company
[EMAIL PROTECTED]
"It's nothing until I call it!" -- Bill Klem, NL Umpire
"When you get the choice to sit it out or dance,
I hope you dance" -- Lee Ann Womack
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