interpolation of unevenly sampled points
- To: mathgroup at yoda.physics.unc.edu
- Subject: interpolation of unevenly sampled points
- From: nb at cs.stanford.edu
- Date: Sat, 23 Jan 93 15:50:40 PST
Hi,
> All I need is a way to resample a set of numbers at specific
> intervals. Each x has a corresponding y, but the x's are not evenly
> spaced. I'd like to space them evenly (so I can plot a surface using
> Mathematica), using some simple interpolation algorithm. I'd write a
> routine myself, but the problems sounds so common I thought someone
> may already have written it. However, nothing this simple appears to
> exist on the Mathematica archive server.
Fit can handle unevenly spaced points, so no need to reinvent the wheel.
Fit[data, funs, vars] finds a least-squares fit to a list
of data as a linear combination of the functions funs
of variables vars. The data can have the form {{x1, y1,
..., f1}, {x2, y2, ..., f2}, ...}, where the number of
coordinates x, y, ... is equal to the number of
variables in the list vars. The data can also be of the
form {f1, f2, ...}, with a single coordinate assumed to
take values 1, 2, .... The argument funs can be any
list of functions that depend only on the objects vars.
In[2]:= Fit[{{2,4.7}, {5, 3.4}, {11, 5.6}, {12, 32.7}}, {1, x, x^2}, x]
Out[2]=
2
18.8197 - 7.23175 x + 0.639707 x
Nancy