R 如何使用半一致格式重命名观测值？

我正在使用以下数据帧：

Team       Direction      Side
Joe         HB-L           L
Eric        HB-R           R
Tim         FB-L           R
Mike        HB             L

我想删除“方向”栏中“L”或“R”前面的“HB”或“FB”。我还想消除“方向”列中没有“L”或“R”的观察结果。我希望它看起来像这样：

Team       Direction      Side
Joe         L              L
Eric        R              R
Tim         L              R

然后，我想添加一列，指示“方向”和“侧面”列是否相同。如果是，我希望它读“近”，如果不是，我希望它读“远”

---

我们可以使用

sub

在

base R

中执行此操作，以在根据“方向”中存在的

-

对行进行子设置后，移除子字符串，直到

-

df1 <- subset(df1, grepl('-', Direction))
df1$Direction <- sub(".*-", "",  df1$Direction)

然后，我们可以使用

==

创建一个逻辑条件，将值替换为“远”、“近”

df1$Relation <- with(df1, c('FAR', 'NEAR')[(Direction == Side) + 1])

---

或使用

tidyverse

library(dplyr)
library(stringr)
df1 %>%
     filter(grepl('-', Direction)) %>% 
     mutate(Direction = str_replace(Direction, '.*-', ''), 
        Relation = case_when(Direction == Side ~ 'NEAR', TRUE ~ 'FAR'))
#   Team Direction Side Relation
#1  Joe         L    L     NEAR
#2 Eric         R    R     NEAR
#3  Tim         L    R      FAR

---

或使用

data.table

 library(data.table)
 setDT(df1)[grepl('-', Direction)][, Direction := trimws(Direction,
     whitespace = '.*-')][, Relation := fifelse(Direction == Side, 'NEAR', 'FAR')][]
#   Team Direction Side Relation
#1:  Joe         L    L     NEAR
#2: Eric         R    R     NEAR
#3:  Tim         L    R      FAR

数据

---

df1我们可以首先
过滤
其中包含
“-”
的行，删除所有内容，直到
“-”
为止，并使用
if_else
将
'NEAR'
或
'FAR'
值分配给
关系

library(dplyr)
library(stringr)

df %>%
  filter(str_detect(Direction, '-')) %>%
  mutate(Direction = str_remove(Direction, '.*-'), 
         Relation = if_else(Direction == Side, 'NEAR', 'FAR'))

#  Team Direction Side Relation
#1  Joe         L    L     NEAR
#2 Eric         R    R     NEAR
#3  Tim         L    R      FAR

library(dplyr)
library(stringr)
df1 %>%
     filter(grepl('-', Direction)) %>% 
     mutate(Direction = str_replace(Direction, '.*-', ''), 
        Relation = case_when(Direction == Side ~ 'NEAR', TRUE ~ 'FAR'))
#   Team Direction Side Relation
#1  Joe         L    L     NEAR
#2 Eric         R    R     NEAR
#3  Tim         L    R      FAR

 library(data.table)
 setDT(df1)[grepl('-', Direction)][, Direction := trimws(Direction,
     whitespace = '.*-')][, Relation := fifelse(Direction == Side, 'NEAR', 'FAR')][]
#   Team Direction Side Relation
#1:  Joe         L    L     NEAR
#2: Eric         R    R     NEAR
#3:  Tim         L    R      FAR

df1 <- structure(list(Team = c("Joe", "Eric", "Tim", "Mike"), Direction = c("HB-L", 
"HB-R", "FB-L", "HB"), Side = c("L", "R", "R", "L")),
class = "data.frame", row.names = c(NA, 
-4L))

library(dplyr)
library(stringr)

df %>%
  filter(str_detect(Direction, '-')) %>%
  mutate(Direction = str_remove(Direction, '.*-'), 
         Relation = if_else(Direction == Side, 'NEAR', 'FAR'))

#  Team Direction Side Relation
#1  Joe         L    L     NEAR
#2 Eric         R    R     NEAR
#3  Tim         L    R      FAR