Re: [R] Smoothing z-values according to their x, y positions

From: David Winsemius <>
Date: Thu, 20 Mar 2008 01:40:17 +0000 (UTC)

"Emmanuel Levy" <> wrote in

> Dear Bert,
> Thanks for your reply - I indeed saw a lot of functions using:
> The problem is that most seem to not be very appropriate to what I'd
> like, or they seem extremely complicated (e.g. gma). I am probably
> missing something as I don't
> see how to use Loess. From my poor understanding, it seems to be for
> 2D data. Here I want to smooth the third "z" component.
> In the meantime I adapted a function from Greg Warnes, which sort of
> does the job (although the smoothing is not very nice).
> So I'd be very happy to learn how do do something similar with
> loess!

You could consider at combining the kde2d() function in the MASS package within the VR bundle in combination with contour(). The example I followed came from MASS 2ed in chapter 5's section on density estimation. It is probably easiest to just copy the help example:

f1 <- kde2d(duration[-272], duration[-1],

             h = rep(1.5, 2), n = 50, lims = c(0.5, 6, 0.5, 6)) contour(f1, xlab = "previous duration",

        ylab = "duration", levels = c(0.05, 0.1, 0.2, 0.4) )

I have also had success with Loader's locfit package.

David Winsemius

______________________________________________ mailing list
PLEASE do read the posting guide
and provide commented, minimal, self-contained, reproducible code.
Received on Thu 20 Mar 2008 - 01:45:18 GMT

Archive maintained by Robert King, hosted by the discipline of statistics at the University of Newcastle, Australia.
Archive generated by hypermail 2.2.0, at Thu 20 Mar 2008 - 05:30:22 GMT.

Mailing list information is available at Please read the posting guide before posting to the list.

list of date sections of archive