将矢量压缩成逗号分隔字符串

Question

如何将unique的结果压缩为逗号分隔字符串？

temp3 <- data.frame(categoryId=c(1,1,1,2),ballot1=c("yes","yes","no","200")) 
temp3 %>% group_by(categoryId) 
     %>% mutate(responses=unique(ballot1)) 

预期输出：

1 yes,no 
1 yes,no 
1 yes,no 
2 200 

Answer 1

我们可以按 '的categoryId'，获得 'ballot1' 和paste在一起

library(dplyr) 
temp3 %>% 
    group_by(categoryId) %>% 
    mutate(ballot1 = toString(unique(ballot1))) 
# A tibble: 4 x 2 
# Groups: categoryId [2] 
# categoryId ballot1 
#  <dbl> <chr> 
#1   1 yes, no 
#2   1 yes, no 
#3   1 yes, no 
#4   2  200