ggplot2:如果位置="fill"，则在条形图上添加标签. [英] ggplot2: Add label on barplot if position = "fill"

问题描述

我想在填充的条形图上添加％数字.这是带有错误位置标签的绘图:

I would like to add %-figures on a filled barplot. Here is the plot with the labels at the wrong places:

以下是数据框:

x0 <- expand.grid(grp    = c("G1","G2")
                 , treat = c("T1","T2")
                 , out   = c("out1","out2","out3","out4")
)
set.seed(1234)
x0$n <- round(runif(16,0,1)*100,0)
head(x0)
  grp treat  out  n
1  G1    T1 out1 11
2  G2    T1 out1 62
3  G1    T2 out1 61
4  G2    T2 out1 62
5  G1    T1 out2 86
6  G2    T1 out2 64

现在，我将grp/treat中的总和添加到数据帧中(使用sql，对不起！):

Now, I add the sum within grp/treat to the dataframe (using sql, sorry!):

x0 <- sqldf(paste("SELECT a.*, (SELECT SUM(n)"
                  ,"            FROM x0 b"
                  ,"            WHERE a.grp = b.grp"
                  ,"                  AND a.treat = b.treat"
                  ,"           ) tot"
                  ," FROM x0 a"
                  ," ORDER BY a.grp,a.treat,a.out"
                  )
            )
x0$p <- with(x0, n/tot)
x0$p2 <- with(x0, paste(formatC(p*100, digits=2
              , format="fg"),"%",sep=""))
head(x0)
  grp treat  out  n tot          p    p2
1  G1    T1 out1 11 192 0.05729167  5.7%
2  G1    T1 out2 86 192 0.44791667   45%
3  G1    T1 out3 67 192 0.34895833   35%
4  G1    T1 out4 28 192 0.14583333   15%
5  G1    T2 out1 61 160 0.38125000   38%
6  G1    T2 out2  1 160 0.00625000 0.62%

这是我获得剧情的方法:

And here is how I get the plot:

ggplot(x0, aes(grp, weight=n)) +
         geom_bar(aes(fill = out), position = "fill") +
         facet_grid(.~treat) +
         scale_y_continuous(labels=percent) +
         geom_text(aes(label=p2, y=p))

我可以使用累积百分比向数据框添加新变量，但我想知道是否有更简单的方法来添加标签.

I could add a new variable to the dataframe with cumulative percentage but I'm wonder if there is a simpler way to add the labels.

推荐答案

为避免自己创建位置值，可以像在

To avoid creating the position values yourself, you can use position = "stack" in geom_text as in this question. As you noted in the comments, the dataset must be ordered by the fill variable to get the stacks in the correct order to match the bar stacks.

ggplot(x0, aes(grp, weight = n)) +
    geom_bar(aes(fill = out), position = "fill") +
    facet_grid(.~treat) +
    scale_y_continuous(labels=percent) +
    geom_text(aes(label = p2, y=p), position = "stack")

您最终可能需要删除一定尺寸以下的标签，以删除上图中的重叠部分. geom_text(aes(label = ifelse(p < .05, NA, p2), y = p), position = "stack")之类的东西会删除非常小的值的标签.

You may end up needing to remove the labels below a certain size to remove the overlap seen in the plot above. Something like geom_text(aes(label = ifelse(p < .05, NA, p2), y = p), position = "stack") would remove labels for the very small values.

这篇关于ggplot2:如果位置="fill"，则在条形图上添加标签.的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！