Problem with circular::plot.circular()

require(circular)
c <- circular(rep(0, 20), zero = pi/2, rotation = 'clock')
plot(c, stack = TRUE, shrink = 1.5)

Can anyone tell me why the stack is offset from 0?

It's a histogram, and the bin starts at zero, and runs to pi/10 (I'm 
guessing, since it appears to choose 20 bins).

You can see the binning effect if you set your data to

c <- circular(runif(20, 0, 2*pi), zero=pi/2, rotation='clock')

Set bins to 10000 and the offset will be undetectable:

plot(c, stack = TRUE, shrink = 1.5, bins=10000)

Duncan Murdoch