R根据列中的其他字符串替换字符串

Question

我在数据框中有列，行中有以下结构。

first cycle
first cycle
shifting cycle
2nd cycle 
2nd cycle
2nd cycle
shifting cycle
3rd cycle
3rd cycle

我想用移位循环的第一个条目替换所有行到移位循环 1 和移位循环的第二个条目到移位循环 2。基本上它是一个字符串操作，我不知道如何去做。是的，我是根据其他列中的值来做的，但是手动查找其他列中的值是不合适的，因为许多文件中的值各不相同。

我的代码

df$column <-str_replace(df$column, "Shifting cycle", "Shifting cycle 2")
df <- df %>% mutate(column = case_when(other_column ==30~ 'Shifting cycle 1' ,T~column))

所以最终输出将是

first cycle
first cycle
shifting cycle 1
2nd cycle
2nd cycle 
2nd cycle
shifting cycle 2
3rd cycle
3rd cycle

Answer 1

使用 cumsum() 作为匹配值的计数器：

library(dplyr)
df %>%
  mutate(
    column =
      case_when(
        column == "shifting cycle" ~ paste(column, cumsum(column == "shifting cycle")),
        TRUE ~ column
      )
  )
#> # A tibble: 9 × 1
#>   column          
#>   <chr>           
#> 1 first.cycle     
#> 2 first cycle     
#> 3 shifting cycle 1
#> 4 2nd cycle       
#> 5 2nd cycle       
#> 6 2nd cycle       
#> 7 shifting cycle 2
#> 8 3rd cycle       
#> 9 3rd cycle

输入数据：

df <- tibble::tribble(
           ~column,
     "first.cycle",
     "first cycle",
  "shifting cycle",
       "2nd cycle",
       "2nd cycle",
       "2nd cycle",
  "shifting cycle",
       "3rd cycle",
       "3rd cycle"
  )

^{创建于 2023-01-30 reprex v2.0.2}

Answer 2

library(tidyverse)

df %>%
  group_by(group = str_detect(cycles, "shifting cycle")) %>%
  mutate(cycles = case_when(
    group == TRUE ~ str_c(cycles, 1:n(), sep = " "),
    TRUE ~ cycles)) %>% 
  ungroup() %>% 
  select(-group)

# A tibble: 9 × 1
  cycles          
  <chr>           
1 first cycle     
2 first cycle     
3 shifting cycle 1
4 2nd cycle       
5 2nd cycle       
6 2nd cycle       
7 shifting cycle 2
8 3rd cycle       
9 3rd cycle