R-ggplot2 geom_line闪避

Question

我在“闪避”的stacked bars上绘制“闪避” line时遇到麻烦。

dt = mtcars %>% group_by(am, cyl) %>% summarise(m = mean(disp))
dt0 = dt[dt$am == 0, ]
dt1 = dt[dt$am == 1, ]

dt0 %>% ggplot(aes(factor(cyl), m, fill = factor(cyl))) + geom_bar(stat = 'identity', position = 'dodge') +
  geom_point(data = dt1, aes(factor(cyl), m, colour = factor(cyl)), position=position_dodge(width=0.9), colour = 'black') 

我想是从叠置条到每个黑点的顶部画一条线cyl 。

dt0 %>% ggplot(aes(factor(cyl), m, fill = factor(cyl))) + geom_bar(stat = 'identity', position = 'dodge') +
  geom_point(data = dt1, aes(factor(cyl), m, colour = factor(cyl)), position=position_dodge(width=0.9), colour = 'black') + 
  geom_line(data = dt1, aes(factor(cyl), m, colour = factor(cyl), group = 1), position=position_dodge(width=0.9), colour = 'black')  

但是， position=position_dodge(width=0.9)躲避在这里不起作用。

任何想法 ？

Answer 1

如果您调整汇总数据的形状，这将更容易实现：

dt <- mtcars %>% 
    group_by(am, cyl) %>% 
    summarise(m = mean(disp)) %>% 
    spread(am, m)

    cyl        0        1
* <dbl>    <dbl>    <dbl>
1     4 135.8667  93.6125
2     6 204.5500 155.0000
3     8 357.6167 326.0000

尽管“ 0”和“ 1”是较差的列名，但是如果在反引号中引用它们，它们仍然可以在aes()使用。 对position_dodge()的调用也变得不必要：

dt %>% ggplot(aes(x = factor(cyl), y = `0`, fill = factor(cyl))) + 
    geom_bar(stat = 'identity') +
    geom_point(aes(x = factor(cyl), y = `1`), colour = 'black') +
    geom_segment(aes(x = factor(cyl), xend = factor(cyl), y = `0`, yend = `1`))