Message-ID: <20051205133629625.00000002036@AVAIL2003>
Date: 2005-12-05T13:36:29Z
From: Stephen A Roberts
Subject: Closed form for regression splines
Greetings,
I have a model fitted using bs() and need to be able to write down a closed form for the spline function to enable the use of the fitted model outside R. Does anyone know a simple way of extracting the piecewise cubics from the coefficients and knots? As far as I know they are defined by recurrence relationships, but the R implementation is buried in C code, and I guess in non-trivial to invert. I know about predict.bs() within R, but I want the full piecewise cubic.
Steve.
Dr Steve Roberts
steve.roberts at manchester.ac.uk
Senior Lecturer in Medical Statistics,
Biostatistics Group,
University of Manchester,