r - 如何将一列中的因子扩展为多列——本质上是将数据集缩短一半？

Question

如何将“strike”列分为“kick_type”和“punch_type”两列，并将“damage”列分为“kick damage”和“punch damage”？

我已经处理了 3 个小时了，但我不知道如何拆分它。请注意，我已经使用 pivot_longer 从不整洁的格式进入这个阶段，其中罢工都是列，所以我之前已经完成了其他步骤，但无法弄清楚。

可重现的代码:

trial <- data.frame(fighter=c("Saenchai","Saenchai","Saenchai","Saenchai","Buakaw","Buakaw","Buakaw","Buakaw"), 
strike=rep(c("roundhouse_kick","side_kick","lefthook_punch","uppercut_punch")),
damage=c(0.7,0.8,0.6,0.3,0.9,0.5,0.7,0.1))

它应该是这样的，但我不知道如何到达那里:

fighter   kick_type         kick_damage   punch_type      punch_damage
Saenchai  roundhouse_kick   0.7           lefthook_punch  0.6
Saenchai  side_kick         0.8           uppercut_punch  0.3

Answer 1

我确信有更好的方法，但这里有一种非正则表达式友好的方法:

library(tidyverse)

trial %>% 
  pivot_wider(names_from = "strike", values_from = "damage") %>% 
  pivot_longer(ends_with('kick'), names_pattern = '(.*)_kick', names_to = "kick_type", values_to = "kick_damage") %>% 
  pivot_longer(ends_with('punch'), names_pattern = '(.*)_punch', names_to = "punch_type", values_to = "punch_damage") %>% 
  group_by(fighter) %>% 
  filter(row_number() == 1 | row_number() == n())

# A tibble: 4 x 5
# Groups:   fighter [2]
  fighter  kick_type  kick_damage punch_type punch_damage
  <chr>    <chr>            <dbl> <chr>             <dbl>
1 Saenchai roundhouse         0.7 lefthook            0.6
2 Saenchai side               0.8 uppercut            0.3
3 Buakaw   roundhouse         0.9 lefthook            0.7
4 Buakaw   side               0.5 uppercut            0.1

---

另一种更简单的方法是使用separate:

trial %>%
  separate(strike, into = c("type", "move")) %>% 
  group_by(fighter, move) %>% 
  mutate(n = row_number()) %>% 
  pivot_wider(c(fighter, n), names_from = move, values_from = c(type, damage))

# A tibble: 4 x 6
# Groups:   fighter [2]
  fighter      n type_kick  type_punch damage_kick damage_punch
  <chr>    <int> <chr>      <chr>            <dbl>        <dbl>
1 Saenchai     1 roundhouse lefthook           0.7          0.6
2 Saenchai     2 side       uppercut           0.8          0.3
3 Buakaw       1 roundhouse lefthook           0.9          0.7
4 Buakaw       2 side       uppercut           0.5          0.1