Clare, `gamm' with an nlme correlation structure uses a gee approach to correlation in the generalized case (it's just likelihood in the gaussian additive case, of course). See the `gamm' help files for examples. However this will usually run out of memory for datasets of size a few hundred to a thousand, unless you can split the data into smaller independent blocks (as in the last example in my book, ref in ?gam)
Simon On Friday 21 January 2011 09:36, Clare Embling wrote: > Hi Simon, > > Thanks for that! Yes the circular variable is a predictor variable - great > that it can be done using GAMs. I actually would like to do a GAM-GEE model > - do you know if I can do this within R yet? I'm using GLM-GEEs because I > can't do GAM-GEEs (I have data collected over the same survey route > repeatedly over time, so want to take into account the fact that my data > are not independent - I'm modelling my correlation structure using an ar-1 > autoregressive correlation structure within a GEE). That way too, I can > include my circular variables with circular smoothing functions as you > suggested. > > Best wishes & thanks, > Clare > > ________________________________________ > From: Simon Wood [s.w...@bath.ac.uk] > Sent: 18 January 2011 17:58 > To: r-help@r-project.org > Cc: Clare Embling > Subject: Re: [R] Circular variables within a GLM, GLM-GEE or GAM > > Is the variable to be used as a predictor? If so mgcv::gam has a couple of > circular smoother built in... > > s(x,bs="cc") or s(x,bs="cp") > > (if the range of x is less than the full [0, 360] then you can supply a > `knots' argument to gam to force the x range to go from 0 to 360, otherwise > s(min(x), bs="c*") will be identical to s(max(x),bs="c*"), which may not be > matching in the right place). > > Simon > > On Tuesday 18 January 2011 12:07, Clare Embling wrote: > > Hi, > > > > I have a variable (current speed direction) which is circular (0=360 > > degrees), and I'd like my GLM to include the variable as a circular > > variable. Can I do this? And what is the code? > > > > I'm actually doing a GLM-GEE using the 'geepack' package, so want to use > > it in that, but also interested in whether it can also be used in GLMs > > and GAMs (I use the 'mgcv' package for GAMs). > > > > Any help would be gratefully received, > > Thanks in advance, > > > > :o) Clare > > > > ______________________________________________ > > 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. > > -- > > > Simon Wood, Mathematical Sciences, University of Bath, Bath, BA2 7AY UK > > +44 1225 386603 www.maths.bath.ac.uk/~sw283 -- > Simon Wood, Mathematical Sciences, University of Bath, Bath, BA2 7AY UK > +44 1225 386603 www.maths.bath.ac.uk/~sw283 ______________________________________________ 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.