[R] CircStats reveals underlying R bug?

[John Christie]

On Nov 12, 2003, at 7:04 AM, Peter Dalgaard wrote:

> John Christie <jc at or.psychology.dal.ca> writes:
>
>> circ.plot in CircStats under R 1.8.0 yields incorrect plots (easily
>> compare hist() and rose.diag()).  However, the code in circ.plot has
>> not changed.  Has anyone tracked this down yet?
>
> Could you supply a directly runnable example, please?

Actually, in making something concise and runnable I found the problem. 
  It is undocumented that circ.plot does not handle negative angles 
while rose.diag does.  I think that should be called a bug in 
circ,plot.  It seems to me the code of these two should be merged 
anyway to avoid future errors.  rose.diag can do a circ.plot type 
diagram (but you always get the rose as well).

So, a simple example is.

x<-rvm(100,1,1)
circ.plot(x, bins=18, stack=T, shrink=2)
rose.diag(x, bins=18, pts=T, shrink=2)
# everything should look OK up until you try comparing the next two 
plots
circ.plot(-x, bins=18, stack=T, shrink=2)
rose.diag(-x, bins=18, pts=T, shrink=2)