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