[R] k-d tree for loess

[Carlisle Thacker]

I am exploring the use of loess for oceanographic applications and would
like to plot the locations (longitude and latitude) points where the models
(salinity~temperature*longitude*latitude,parametric="temperature") are
fitted.  Chambers and Hastie(1993) explains the locations are nodes of a
k-d tree. but I cannot find anything about accessing this information.  It
would be useful to superimpose on such plots contours of the weights for at
least one point.  Sample code of drawing such plots would be greatly
appreciated.

Thanks,

Carlisle Thacker