[R] Strange labels on plot with dates

[Henrik Andersson]

Hello fellow R people,

I don't understand the default behavior of the axis labeling when 
plotting dates.

I would expect something like 2001, 2002 or possibly Jan 01, Jan 
02...Jan 06, but instead I only see Jan 01, Jan 01, Jan 01....


See the following example

startdate <- strptime("2001-01-01",format="%Y-%m-%d")
enddate <- strptime("2006-12-31",format="%Y-%m-%d")
dates <- seq(startdate,enddate,by="month")

daynr <- as.numeric(julian(dates,origin=dates[1]))

yvar <- sin(daynr*2*pi/365)

plot(yvar~dates,type='l')

Cheers, Henrik

-- 
Henrik Andersson

Danish Meteorological Institute
Lyngbyvej 100
2100 Copenhagen Ø
Denmark
Tel: +45 39157215 
Email: han at dmi.dk