向数据添加列。将行均匀分配给列表中的值的框架

Question

我有一个数据框架，其中每一行都是一个家庭，我有一个面试者列表。目的是将面试者分配到家庭，每个面试者应该在每个城市获得相同数量的家庭。例如,

example <- data.frame(city = c("Los Angeles", "Los Angeles", "Los Angeles", 
                               "San Diego", "San Diego", "San Diego", "San Diego", "San Diego",
                               "Santa Barbara", "Santa Barbara", "Santa Barbara", "Santa Barbara", "Santa Barbara"), 
                      household_id = seq(1, 13))
interviewer <- c("A", "B", "C")

所有3名面试者将前往所有城市，并将采访每个城市约三分之一的家庭，因此预期输出为

output <- data.frame(city = c("Los Angeles", "Los Angeles", "Los Angeles", 
                               "San Diego", "San Diego", "San Diego", "San Diego", "San Diego",
                               "Santa Barbara", "Santa Barbara", "Santa Barbara", "Santa Barbara", "Santa Barbara"), 
                      household_id = seq(1, 13),
                     interviewer = c("A", "B", "C",
                                     "A", "A", "B", "B", "C",
                                     "A", "A", "B", "B", "C"))

Answer 1

您可以尝试使用rep为每个city重复interviewer。

library(dplyr)

example %>%
  group_by(city) %>%
  mutate(interviewer = rep(interviewer, length.out = n()))

#   city          household_id interviewer
#   <chr>                <int> <chr>      
# 1 Los Angeles              1 A          
# 2 Los Angeles              2 B          
# 3 Los Angeles              3 C          
# 4 San Diego                4 A          
# 5 San Diego                5 B          
# 6 San Diego                6 C          
# 7 San Diego                7 A          
# 8 San Diego                8 B          
# 9 Santa Barbara            9 A          
#10 Santa Barbara           10 B          
#11 Santa Barbara           11 C          
#12 Santa Barbara           12 A          
#13 Santa Barbara           13 B