On 15/02/2012 15:00, Nicholas Reich wrote:
Hello.
I'm getting an unexpected result when running smooth.spline(). Here
is a simple example that replicates the error I'm getting:
aa<- c(1, 2, 3, 8, 8, 8, 8, 8, 8, 8, 8, 8, 12, 13, 14) bb<-
1:length(aa) plot(aa, bb) smooth.spline(aa, bb)
Error in smooth.spline(aa, bb) : need at least four unique 'x'
values
As you can see from the example, my 'x' clearly has more than 4
values. The problem is the form of my 'x'. When I dig around in the
smooth.spline() code, it looks like it is relying on a call to IQR(x)
which, with data such as the object aa above, returns 0 because more
than half of the values are stacked on one value in the middle of the
data. The call to smooth.spline() works if I add some random noise
to the Xs, but I'd like to be able to avoid that type of workaround.
Any other suggestions?
Read the help page (as the posting guide asked of you) ...
tol: A tolerance for same-ness of the ‘x’ values. The values are
binned into bin of size ‘tol’ and values which fall into the
same bin are regarded as the same.
Works with tol = 0.1, for example. IQR is only used in the default for
that argument.
Thanks, Nick
--
Brian D. Ripley, rip...@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 272866 (PA)
Oxford OX1 3TG, UK Fax: +44 1865 272595
______________________________________________
R-help@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
