Re: Spline
- To: mathgroup at smc.vnet.net
- Subject: [mg58307] Re: Spline
- From: Bill Rowe <readnewsciv at earthlink.net>
- Date: Sun, 26 Jun 2005 23:13:09 -0400 (EDT)
- Sender: owner-wri-mathgroup at wolfram.com
On 6/26/05 at 1:33 AM, davidannetts at aapt.net.au (David Annetts) wrote: >If you know the values at the endpoints, then tell the spline >routine. There's no way of extending the spline, since it is only >defined (in the original) on [.1, .9]. Not true. For a given set of points a natural cubic spline is created by setting the second derivative to 0 at the end points and requiring continuity of both the first and second derivative at all points. So, past the end points, the curve will be a line (continuous first derivative, second and higher derivatives = 0) However, it is true the package SplineFit will not extend the spline past the end points in the original data set. -- To reply via email subtract one hundred and four