R中的新客户或老客户

Question

我有以下数据集，它已经按事务排序：

dataset <- data.frame(id = c(1,2,3,4,2,4,6,7,3,2),
                      transaction = c(1,2,3,4,5,6,7,8,9,10),
                      amount = c(200,100,50,100,50,300,100,50,100,50))

如您所见，每个客户都有一个Id和在交易中花费的金额。

我的问题是，如何识别客户是交易中的新客户，还是反复出现的客户。新客户意味着这是它的第一笔交易，下一笔交易是重复的。

recurrence_status <- c("new","new","new","new","recurrent",
"recurrent","new","new","recurrent","recurrent")

到目前为止，我已经尝试了以下几种方法：

for (i in 1:(length(dataset$transaction)-1)){
  for(j in 2:length(dataset$transaction)){
    j <- j + 1
    comp <- dataset[j:length(dataset$id)]
    ifelse((is.element(dataset[i,1]),comp),"recurrent","new")
  }
}

但是由于括号的原因，它给了我一个错误。我知道应该尽可能避免在R中使用循环。请不要客气，我们欢迎您的帮助。

致以敬意，

Answer 1

在base R中，这可以通过duplicated来完成

dataset$recurrence_status  <- c("new", "recurrent")[duplicated(dataset$id) + 1]
dataset$recurrence_status 
#[1] "new"       "new"       "new"       "new"       "recurrent" "recurrent" "new"       "new"       "recurrent"
#[10] "recurrent"

Answer 2

利用dplyr

dataset %>%
 group_by(id) %>%
 mutate(recurrence_status = factor(+(row_number() > 1), 
                                   levels = c(0, 1), 
                                   labels = c("new", "recurrent")))

      id transaction amount recurrence_status
   <dbl>       <dbl>  <dbl> <fct>            
 1     1           1    200 new              
 2     2           2    100 new              
 3     3           3     50 new              
 4     4           4    100 new              
 5     2           5     50 recurrent        
 6     4           6    300 recurrent        
 7     6           7    100 new              
 8     7           8     50 new              
 9     3           9    100 recurrent        
10     2          10     50 recurrent