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'.
"Barry Williams" <email@example.com> wrote in message <firstname.lastname@example.org>... > "Anil Kumar Palaparthi" wrote in message <email@example.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