将geom_text放置在geom_col堆叠的条形图中每个条形段的中间 [英] Position geom_text in the middle of each bar segment in a geom_col stacked barchart

问题描述

我想将相应的值标签放置在每个条形段中间的geom_col堆叠条形图中.

I would like to position the corresponding value labels in a geom_col stacked barchart in the middle of each bar segment.

但是，我的幼稚尝试失败了.

However, my naive attempt fails.

library(ggplot2) # Version: ggplot2 2.2

dta <- data.frame(group  = c("A","A","A",
                             "B","B","B"),
                  sector = c("x","y","z",
                             "x","y","z"),
                  value  = c(10,20,70,
                             30,20,50))

ggplot(data = dta) +
  geom_col(aes(x = group, y = value, fill = sector)) +
  geom_text(position="stack",
            aes(x = group, y = value, label = value)) 

很明显，将y=value/2设置为geom_text也无济于事.此外，文本的位置顺序错误(颠倒了).

Obviously, setting y=value/2 for geom_text does not help, either. Besides, the text is positioned in the wrong order (reversed).

任何(优雅的)想法如何解决这个问题?

Any (elegant) ideas how to solve this?

推荐答案

您需要将一个变量映射到一个美学对象，以表示geom_text中的组.对于您来说，这是您的"sector"变量.您可以将其与geom_text中的group美感搭配使用.

You need to have a variable mapped to an aesthetic to represent the groups in geom_text. For you, this is your "sector" variable. You can use it with the group aesthetic in geom_text.

然后使用position_stack和vjust将标签居中.

Then use position_stack with vjust to center the labels.

ggplot(data = dta) +
    geom_col(aes(x = group, y = value, fill = sector)) +
    geom_text(aes(x = group, y = value, label = value, group = sector),
                  position = position_stack(vjust = .5))

您可以通过全局设置美学来节省一些打字.然后fill将用作geom_text的分组变量，您可以跳过group.

You could save some typing by setting your aesthetics globally. Then fill would be used as the grouping variable for geom_text and you can skip group.

ggplot(data = dta, aes(x = group, y = value, fill = sector)) +
    geom_col() +
    geom_text(aes(label = value),
              position = position_stack(vjust = .5))

这篇关于将geom_text放置在geom_col堆叠的条形图中每个条形段的中间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！