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Topic: interpolation on geometric progression data
Replies: 4   Last Post: Jan 15, 2013 5:19 PM

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 Anil Kumar Palaparthi Posts: 21 Registered: 6/2/10
Re: interpolation on geometric progression data
Posted: Jan 15, 2013 3:45 PM

From Geometric Progression, what I mean is that the data is not sampled uniformly or in linear sequence. It is sampled in geometric sequence.
For example, y = f(x) where 'x' is sampled in geometric sequence not in linear sequence and I can't fit any polynomial to 'f'.

-Anil Palaparthi.

"Barry Williams" <barry.r.williamsnospam@saic.com> wrote in message <kd4d6v\$pv0\$1@newscl01ah.mathworks.com>...
> "Anil Kumar Palaparthi" wrote in message <kd4acs\$eja\$1@newscl01ah.mathworks.com>...
> > Hi,
> >
> > I need to interpolate my data whose 'x' values are in geometric progression rather than linear. For example, x = [0.005,0.01,0.02,0.04,0.08] and 'y' can be anything.
> > Can anyone suggest me how I can interpolate this kind of data?
> > Is there a specific algorithm that can interpolate geometric progression data?
> >
> > Best Regards,
> > Anil Palaparthi.

>
> What I prefer to do whenever possible is to interpolate from the underlying function. If by *geometric progression* you are referring to a polynomial of form:
> y = a0 + a1(x) + a2(x^2 + a3(x^3) ...
> Then you could fit the data to the polynomial, and then use polyval to evaluate it at the needed values of x.
> If you have no idea of the for f(x) takes, then dpb is right. The method you use with interp1 is irrelevant.
> Barry

Date Subject Author
1/15/13 Anil Kumar Palaparthi
1/15/13 dpb
1/15/13 Barry Williams
1/15/13 Anil Kumar Palaparthi
1/15/13 Derek Goring