添加geom_path和geom_text相同的ggplot生成R錯誤

Question

我繪製geom_path對象，並在同一ggplot一個geom_text對象，但我遇到了以下問題：

#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)) 

但得到的錯誤 錯誤在eval（expr，envir，enclos）：object'site'not found

任何想法？

Answer 1

主要ggplot調用中的每種美學都會在每個後續geom_中預期。解決方法是移動label = site或將其取消映射到geom_path，方法是將其設置爲NULL。

Answer 2

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