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Re: polyfit problem?
From: |
Haisam K. Ido |
Subject: |
Re: polyfit problem? |
Date: |
Tue, 16 Mar 1999 23:03:44 +0000 (GMT) |
On Tue, 16 Mar 1999 address@hidden wrote:
> Hi -
> > When I use octave to get a 9th degree polynomial for xy below, via
> > polyfit I get very strange coefficients, while when I use gnuplot's fit
> > capability on the same data I get reasonable coefficients.
>
> octave's polyfit does no pre-scaling before setting up the matrix.
> I find that necessary for any kind of real work with polynomial fits.
> When I ran into this, I prescaled the data before calling polyfit,
> rather than "fixing" polyfit. Sorry.
I don't know what you mean by pre-scaling.