Re: [Splines] Defining piecewise functions over a variable number of intervals

*To*: mathgroup at smc.vnet.net*Subject*: [mg52724] Re: [Splines] Defining piecewise functions over a variable number of intervals*From*: Bill Rowe <readnewsciv at earthlink.net>*Date*: Sat, 11 Dec 2004 05:21:18 -0500 (EST)*Sender*: owner-wri-mathgroup at wolfram.com

On 12/9/04 at 8:22 PM, phloam at myrealbox.com (m0NoiD) wrote: >I know you can define a function piecewise with If[] statements, >and even better with Which[]. I am wondering if there is a way to >construct a piecewise function when the number of intervals is not >known in advance. >I am trying to find a way to compute cubic splines for any number >of data points. The data points will be the input. Then it will >compute the coefficients of the polynomials. >The thing I then need is a subroutine which will take any number of >coefficients as input and construct piecewise cubic polynomials. >I am looking for the most efficient way to do this. I am guessing >it will require some sort of pattern matching, but I am not sure so >that is why I need help. There are fairly efficient algorithms for computing a natural cubic spline that do not require pattern matching. Take a look at the code in NumericalMath`SplineFit` for an example. In fact, if all you need is a cubic spline to represent a set of points, the function SplineFit in that package already does this. -- To reply via email subtract one hundred and four