I have a dataframe with columns A and B where B is a character string I want to groupby column A and the combine the elements of B into a string where I can then get the unique elements of that grouped characters (using R 4.0.5 and dplyr).

Example:

df <- data.frame(a = c("a","a","a","b","b","b"), c = c("d","d","d","d","e","e"))

df.new <- df %>%
             group_by(a) %>%
             summarise(new_strs = c(c)) 

which outputs this data.frame:

1 a     d       
2 a     d       
3 a     d       
4 b     d       
5 b     e       
6 b     e    

Desired DF output:

1 a     c("d","d","d")             
6 b     c("d","e","e")    

How can I change the code to get the result. I also tried paste(x, collapse = ",") but it gives a single string rather then a group of strings.

CodePudding user response：

My first thought is to use list rather than c

exampledf <- data.frame(a = c("a","a","a","b","b","b"), c = c("d","d","d","d","e","e"))

exampledf %>%
  group_by(a) %>%
  summarise(new_strs = list(c))

CodePudding user response：

We may use aggregate from base R

aggregate(c ~ a, df, list)
  a       c
1 a d, d, d
2 b d, e, e