Adding geom_path and geom_text to the same ggplot

问题:

I am plotting a geom_path object and a geom_text object in the same ggplot but am running into the following problem:

#load the data frames
df1 <- data.frame(x=c(32, 42, 52), y=c(15, 20, 25), grp=c(1, 2, 2), site=c("A", "B", "C"))
df1$grp = factor(df1$grp)
colnames(df1)[3] = "Group"

df2 <- data.frame(x=c(32, 42, 52), y=c(15, 20, 25))

#create basic plot with site name coloured by group 
p = ggplot(df1, aes(x=x, y=y, label=site))
p = p + geom_text(aes(colour=factor(Group)), size=4)
p = p + coord_fixed()

#I try adding a path
p = p + geom_path(data=df2, aes(x=x, y=y)) 

But get the error Error in eval(expr, envir, enclos) : object 'site' not found

Any ideas?

回答1:

Every aesthetic in the main ggplot call is expected in every subsequent geom_. The solution is either to move label = site or unmap it in geom_path by setting it to NULL there.

回答2:

ggplot(df1, aes(x, y)) + 
geom_text(aes(label = site, colour = factor(Group)), size = 4) +
coord_fixed() + geom_path(df2, aes(x, y))