r - 缺少显示在底部的类别

Question

我希望“缺失”类别显示在 groupby 之后结果的底部。 x 列中可以有任何字符值。请参阅下面的示例。

library(dplyr)
df <- data.frame(x = c('Ap','LA','MN', 'Missing','ZA'),
                 y = c('PA','NA','DN', 'Missing','ZD'),
                 z = 1:5,
                 stringsAsFactors = F)

df %>% group_by(x) %>% summarise(x1 = sum(z))

Answer 1

Soultion 使用 dplyr::arrange:

df %>% group_by(x) %>%
  summarise(x1 = sum(z)) %>%
  arrange(x == "Missing", x)

返回:

# A tibble: 5 x 2
  x          x1
  <chr>   <int>
1 Ap          1
2 LA          2
3 MN          3
4 ZA          5
5 Missing     4