Suppose I want to build a graph with points and lines, where points appear in front of their respective lines in each group. In particular, I want group 1 to be built with red filled dots where the points are connected by a line, but group 2 should be built with a (just) blue line, but I want group 2 to be built over group 1. For example, in base chart:
set.seed(101)
dd <- data.frame(x=rep(1:10,2),
y=rep(1:10,2),
f=factor(rep(1:2,each=10)))
dd$y[11:20] <- dd$y[11:20] + rnorm(10)
d1 <- subset(dd,f=="1")
d2 <- subset(dd,f=="2")
par(cex=1.5)
plot(y~x,data=d1,bg="red",pch=21,type="o")
lines(y~x,data=d2,col="blue",lwd=2)
legend("bottomright",c("group 1","group 2"),
col=c("black","blue"),
pch=c(21,NA),
pt.bg=c("red",NA),
lty=1,
lwd=c(1,2))

(My real data is a little more complicated.) I'm going to make some nuts trying to do this in ggplot2.
If I draw dots in front of the lines, the points of the 1st group are superimposed with lines in the same group:
library(ggplot2); theme_set(theme_bw())
g0 <- ggplot(dd,aes(x,y,fill=f,colour=f,shape=f))+
scale_fill_manual(values=c("red",NA))+
scale_colour_manual(values=c("black","blue")) +
scale_shape_manual(values=c(21,NA))
g0 + geom_point()+ geom_line()
ggsave("order2.png",width=3,height=3)

If I draw lines in front of the points, the lines of group 2 are superimposed with the points of group 1:
g0 + geom_line()+ geom_point()
ggsave("order3.png",width=3,height=3)

( 1- ), ( 1- ), ( 2). , , , .
g0 + geom_line() + geom_point()+
geom_point(data=d1)+
geom_line(data=d2,show.legend=FALSE)
ggsave("order4.png",width=3,height=3)
, "" geom_linepoint, ; ... - ?
