On Wed, 14 Aug 2002, Oliver Kullmann wrote:
> I would like like to compute first and second derivative
> from numerical data. I hoped I could compute a spline
> object from the data (that works), and then compute the
> derivative from that spline objects, but I couldn't find
> anything like that.
Package pspline on CRAN will fit a spline to data and then predict
its derivatives.
smooth.spline in package modreg will do the same thing, but only for
cubic splines where the second derivative is piecewise linear.
A quintic spline would be a better idea, and pspline allows that.
--
Brian D. Ripley, ripley at stats.ox.ac.uk
Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/
University of Oxford, Tel: +44 1865 272861 (self)
1 South Parks Road, +44 1865 272860 (secr)
Oxford OX1 3TG, UK Fax: +44 1865 272595
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