ggplot pie chart start in anti-clockwise direction while coord_polar(direction=1)

[Botao Fa]

Hi there,

    

      I am using ggplot2 package to get a pie chart. The direction is anti-clockwise while I was using coord_polar with the default parameter (direction=1).

After testing with the classical code online, the result is still strange.

Here is the code:

#' # A pie chart = stacked bar chart + polar coordinates
pie <- ggplot(mtcars, aes(x = factor(1), fill = factor(cyl))) +
 geom_bar(width = 1)
pie + coord_polar(theta = "y")

The chart online is A(http://docs.ggplot2.org/current/coord_polar.html),  my result is B. Can anyone known tell how dose this happen?

A                                                                                                                                                                         B    

Many thanks!

Bert, F