Berwin,
Thanks, I've merged this (second version) patch into 2.8.0 beta.
Brian
On Tue, 7 Oct 2008, Berwin A Turlach wrote:
On Tue, 7 Oct 2008 19:31:03 +0800
Berwin A Turlach <[EMAIL PROTECTED]> wrote:
The attached patch (against the current SVN version of R) implements
the latter strategy. With this patch applied, "make check
FORCE=FORCE" passes on my machine. The version of R that is build
seems to give the correct answer in your example:
Perhaps I should have thought a bit more about this. For a natural
spline c[1] is zero, and d[1] is typically not but for evaluations
left of the first knot it should be taken as zero. So the attached
patch solves the problem in what some might consider a more elegant
manner. :)
With the patch "make check FORCE=FORCE" works on my machine and it
also solves your example:
R> x <- 1:10
R> y <- sin(x)
R>
R> splfun <- splinefun(x,y, method='natural')
R>
R> # these should be linear (and are)
R> splfun( seq(0,1, 0.1) )
[1] 0.5682923 0.5956102 0.6229280 0.6502459 0.6775638 0.7048816
[7] 0.7321995 0.7595174 0.7868352 0.8141531 0.8414710
R>
R> # these should all be the same
R> splfun( seq(0,1, 0.1), deriv=1 )
[1] 0.2731787 0.2731787 0.2731787 0.2731787 0.2731787 0.2731787
[7] 0.2731787 0.2731787 0.2731787 0.2731787 0.2731787
R>
R> # these should all be 0
R> splfun( seq(0,1, 0.1), deriv=2 )
[1] 0 0 0 0 0 0 0 0 0 0 0
R> splfun( seq(0,1, 0.1), deriv=3 )
[1] 0 0 0 0 0 0 0 0 0 0 0
HTH.
Cheers,
Berwin
=========================== Full address =============================
Berwin A Turlach Tel.: +65 6516 4416 (secr)
Dept of Statistics and Applied Probability +65 6516 6650 (self)
Faculty of Science FAX : +65 6872 3919
National University of Singapore
6 Science Drive 2, Blk S16, Level 7 e-mail: [EMAIL PROTECTED]
Singapore 117546 http://www.stat.nus.edu.sg/~statba
--
Brian D. Ripley, [EMAIL PROTECTED]
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 272866 (PA)
Oxford OX1 3TG, UK Fax: +44 1865 272595
______________________________________________
R-devel@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-devel
