[R] locfit troubles

[William T Morgan]

Dear R experts,

We've been playing with the locfit package and are experiencing a
problem I am hoping for some help on.

We have a dataset of 13k points, one dimension of which is "judgment",
either 0 or 1, and the other "score", an arbitrary scalar (in this case
it's between .65 and .85). We use

  locfit(judgement~score,kern="rect",deg=0,family="normal",alpha=c(alpha0,alpha1))

which is the simplest scenario we can think of (though not the one we
would like to use ultimately). The problem: under very small alpha1s
(e.g. 0.001), we see the warning "newsplit: out of vertex space" and
locfit produces a non-sensical output.

Does anyone know the source of this warning? More importantly, are we
mistaken in our usage of such a small alpha1? (The scores are very
tightly packed; there are no windows of size .001 without at least
a few datapoints).

Thank you for your help.

-- 
William T Morgan <wmorgan at mitre.org>
The Mitre Corporation