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

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 Barry Williams Posts: 312 Registered: 6/14/06
Re: interpolation on geometric progression data
Posted: Jan 15, 2013 3:12 PM

"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