I just got 141 hits from 'RSiteSearch("circular data")'. From this,
I quickly learned of two contributed packages for circular data:
"circular" and "CircStats". Both seem to be current, and both are
maintained by the same person.
If you can compute a likelihood for a particular model, then you can
test for equality of parameters between two data sets as follows:
logLik1 = log(likelihood for data set 1 fit by itself.
logLik2 = log(likelihood for data set 2 fit by itself.
logLik12= log(likelihood for data sets 1 and 2 fit as one.
If k parameters are fit for each model, then 2*log(likelihood ratio)
should be approximately chi-square(k). From this you can get a p-value
to compare any pair of data sets. Then use Bonferroni, multiplying each
p-value by, say, (k-1). Any p-value(s) below your Bonferroni-adjusted
threshold could be claimed to be significantly different.
If this is not adequate, I suggest you download both packages (if you
have not already), try them, and then send a question to the maintainer.
If you would like more help from the listserve, I suggest you PLEASE
do read the posting guide! "www.R-project.org/posting-guide.html".
Also, please install the "fortunes" package and read especially