I have the following simple R code.
vect <- c(a = 4, b = 7, c = 5)
pie(vect, labels = c("A", "B", "C"), col = c("#999999", "#6F6F6F", "#000000"))
that print the following pie chart

How do I modify the above code to print more detail on my pie chart, so that it look like this other one ?

Thanks for any reply !
My above comment in details:
Create a dummy data frame for the example:
Call
ggplotfor a pie-chart (coord_polar) based on the manual:Tweak it:
Resulting in: