r - ggplot2:在每个方面从最高到最低重新排列条形

Question

这个问题已经有答案了:

ggplot bar plot with facet-dependent order of categories (4 个回答)

已关闭 6 年前。

在 df下面，我想将每个方面从最高到最低的条形重新排序

我试过了

df <- df %>% tidyr::gather("var", "value", 2:4)
ggplot(df, aes (x = reorder(id, -value), y = value, fill = id))+
  geom_bar(stat="identity")+facet_wrap(~var, ncol =3)

它给了我

它没有对每个方面的条形从最高到最低进行排序。

我想出了另一种方法来获得我想要的东西。我必须一次绘制每个变量，然后使用 grid.arrange() 组合所有图。

#I got this function from @eipi10's answer
#http://stackoverflow.com/questions/38637261/perfectly-align-several-plots/38640937#38640937  
#Function to extract legend
# https://github.com/hadley/ggplot2/wiki/Share-a-legend-between-two-ggplot2-graphs
g_legend<-function(a.gplot) {
  tmp <- ggplot_gtable(ggplot_build(a.gplot))
  leg <- which(sapply(tmp$grobs, function(x) x$name) == "guide-box")
  legend <- tmp$grobs[[leg]]
  return(legend)
}

p1 <- ggplot(df[df$var== "A", ], aes (x = reorder(id, -value), y = value, fill = id))+
  geom_bar(stat="identity") + facet_wrap(~var, ncol =3)

fin_legend <- g_legend(p1)
p1 <- p1 + guides(fill= F)

p2 <- ggplot(df[df$var== "B", ], aes (x = reorder(id, -value), y = value, fill = id))+
  geom_bar(stat="identity") + facet_wrap(~var, ncol =3)+guides(fill=FALSE) 

p3 <- ggplot(df[df$var== "C", ], aes (x = reorder(id, -value), y = value, fill = id))+
  geom_bar(stat="identity") + facet_wrap(~var, ncol =3)+guides(fill=FALSE) 


grid.arrange(p1, p2, p3, fin_legend, ncol =4, widths = c(1.5, 1.5, 1.5, 0.5))

结果就是我想要的

我想知道是否有一种简单的方法可以帮助我在所有方面从最高到最低对条形进行排序，而不必单独绘制每个变量然后将它们组合起来。任何建议将不胜感激。

数据

df <-  read.table(text = c("
id  A   B   C
site1   10  15  20
site2   20  10  30
site3   30  20  25
site4   40  35  40
site5   50  30  35"), header = T)

Answer 1

下面的方法使用 facet_wrap() 为 x 轴专门准备的变量，但使用 labels 参数来 scale_x_discrete()显示正确的 x 轴标签:

准备数据

我对data.table比较熟悉，所以这里用的是这个。请随意使用您喜欢的数据操作包。

编辑:删除了第二个虚拟变量，仅需要ord

library(data.table)   
# reshape from wide to long
molten <- melt(setDT(df), id.vars = "id")
# create dummy var which reflects order when sorted alphabetically
molten[, ord := sprintf("%02i", frank(molten, variable, -value, ties.method = "first"))]

molten
#       id variable value ord
# 1: site1        A    10  05
# 2: site2        A    20  04
# 3: site3        A    30  03
# 4: site4        A    40  02
# 5: site5        A    50  01
# 6: site1        B    15  09
# 7: site2        B    10  10
# 8: site3        B    20  08
# 9: site4        B    35  06
#10: site5        B    30  07
#11: site1        C    20  15
#12: site2        C    30  13
#13: site3        C    25  14
#14: site4        C    40  11
#15: site5        C    35  12

创建绘图

library(ggplot2)
# `ord` is plotted on x-axis instead of `id`
ggplot(molten, aes(x = ord, y = value, fill = id)) +
  # geom_col() is replacement for geom_bar(stat = "identity")
  geom_col() +
  # independent x-axis scale in each facet, 
  # drop absent factor levels (not the case here)
  facet_wrap(~ variable, scales = "free_x", drop = TRUE) +
  # use named character vector to replace x-axis labels
  scale_x_discrete(labels = molten[, setNames(as.character(id), ord)]) + 
  # replace x-axis title
  xlab("id")

数据

df <- read.table(text = "
id  A   B   C
site1   10  15  20
site2   20  10  30
site3   30  20  25
site4   40  35  40
site5   50  30  35", header = T)