R：如何在字符串中添加自定义字符取决于组？

Question

如何在包含变量的字符串中添加自定义字符取决于组变量？

这是虚拟输入数据集：

library(tidyverse)
unit <- c(50, 50, 40, 40, 30, 30, 20, 20, 10, 10)

id <- c("A100", "A101", "A102", "A103", "A100", "A101", "A102", "A103", "A101", "A100")
variation <- c("aaa1", "aaa1", "bbb1", "aaa2", "b1","a3", "a1", "b1", "a1", "b1" )
result <- c("Way1", "Way1", "Way2", "Way2", "Way3","Way1", "Way2", "Way3", "Way4", "Way1" )

data <- data.frame(id, variation, result, unit)
head(data)

#      id variation result unit
# 1  A100      aaa1   Way1   50
# 2  A101      aaa1   Way1   50
# 3  A102      bbb1   Way2   40
# 4  A103      aaa2   Way2   40
# 5  A100        b1   Way3   30
# 6  A101        a3   Way1   30
# 7  A102        a1   Way2   20
# 8  A103        b1   Way3   20
# 9  A101        a1   Way4   10
# 10 A100        b1   Way1   10

是否可以根据“单位”列在“变体”列中添加自定义字符串字符？

这是预期的输出::

#         id variation result unit
# 1  A100      A1.aaa1   Way1   50
# 2  A101      A1.aaa1   Way1   50
# 3  A102      A2.bbb1   Way2   40
# 4  A103      A2.aaa2   Way2   40
# 5  A100        A3.b1   Way3   30
# 6  A101        A3.a3   Way1   30
# 7  A102        A4.a1   Way2   20
# 8  A103        A4.b1   Way3   20
# 9  A101        A5.a1   Way4   10
# 10 A100        A5.b1   Way1   10

如您所见，如果“unit”变量相同，则相同的自定义字符串会添加到该“variation”变量中。

首选 dplyr 和基本 R 函数。

Answer 1

data |> mutate(variation = paste0("A", cumsum(unit != lag(unit, default = first(unit))) + 1,".", variation))

输出：

     id variation result unit
1  A100   A1.aaa1   Way1   50
2  A101   A1.aaa1   Way1   50
3  A102   A2.bbb1   Way2   40
4  A103   A2.aaa2   Way2   40
5  A100     A3.b1   Way3   30
6  A101     A3.a3   Way1   30
7  A102     A4.a1   Way2   20
8  A103     A4.b1   Way3   20
9  A101     A5.a1   Way4   10
10 A100     A5.b1   Way1   10