r - ggplot : order of factors with duplicate levels

Question

ggplot 更改了我不想要的轴变量的顺序。我知道我可以将变量更改为一个因子并指定级别来解决这个问题，但是如果级别包含重复值怎么办？

下面是一个例子。我能想到的唯一选择是使用 reorder() ，但我无法保留变量的原始顺序。

require(ggplot2)
season <- c('Sp1', 'Su1', 'Au1', 'Wi1', 'Sp2', 'Su2', 'Au2', 'Wi2', 'Sp3', 'Su3', 'Au3', 'Wi3') # this is the order I want the seasons to appear in
tempa <- rnorm(12, 15)
tempb <- rnorm(12, 20)

df <- data.frame(season=rep(season, 2), temp=c(tempa, tempb), type=c(rep('A',12), rep('B',12)))


# X-axis order wrong:
ggplot(df, aes(x=season, y=temp, colour=type, group=type)) + geom_point() + geom_line()

# X-axis order correct, but warning of duplicate levels in factor
df$season2 <- factor(df$season, levels=df$season)
ggplot(df, aes(x=season2, y=temp, colour=type, group=type)) + geom_point() + geom_line()

Answer 1

就这样这有一个答案，这很好用:

df$season2 <- factor(df$season, levels=unique(df$season))
ggplot(df, aes(x=season2, y=temp, colour=type, group=type)) + 
   geom_point() + 
   geom_line()