Hello, Is the an analogous function to splinefun or approxfun for multivariate data sets? For example, if I have a data set w/ x's and corresponding y's, I can use either splinefun or approx fun to find values of y for interpolated values of x. Now, what if I want to do the same thing except with a 3 dim. system? If I have a data set with x's, y's, and corresponding z's, is there any way to get a best fit interpolated value (not just an image from the interp command in the akima package) of z for given x and y values? thanks for the help, colby tanner --------------------------------- Use Photomail to share photos without annoying attachments. [[alternative HTML version deleted]]