Re: BUG or FEATURE in Interpolation ?
- To: mathgroup at smc.vnet.net
- Subject: [mg4632] Re: BUG or FEATURE in Interpolation ?
- From: Harald Berndt <haraldb at nature.berkeley.edu>
- Date: Thu, 22 Aug 1996 03:54:51 -0400
- Organization: University of California Forest Products Lab
- Sender: owner-wri-mathgroup at wolfram.com
Stefan Schulz wrote: > ... > I found to my surprise, that the function returned by Interpolation > is not smooth at some of the data points! Well, it is documented: The Book says that the approximated function varies smoothly between sample points, nothing about smoothness of derivatives at sample points. And if you set InterpolationOrder -> 1, you get just plain linear interpolation. >For this reason I resorted to > write a package Spline1D which returns a smooth cubic spline as a > pure function, but is naturally slower than the built-in Interpolation > command. You could probably have used the "Graphics`Spline`" standard package. >Did I find a bug or is this a feature? If it is a feature > it certainly makes the Interpolation command not suitable to obtain > smooth curves. There's also InterpolatingPolynomial (which returns something you probably don't want in your particular example) and of course Fit or NonlinearFit. -- _______________________________________________________________ Harald Berndt University of California Research Specialist Forest Products Laboratory Phone: 510-215-4224 FAX:510-215-4299 _______________________________________________________________ ==== [MESSAGE SEPARATOR] ====