use dplyr to concatenate a column [duplicate]

Answer 1

My data frame was as:
col1 col2

1           one 
1           one more
2           two
2           two
3           three

I needed to summarise it as follows:

col1 col3

1           one, one more
2           two
3           three

This following code did the trick:

    df <- data.frame(col1 = c(1,1,2,2,3), col2 = c("one", "one more", "two", "two", "five"))

    df %>%
            group_by(col1) %>%
            summarise( col3 = toString(unique(col2)))

Answer 2

You need to collapse the values in paste

df %>% group_by(id) %>% summarise(vector=paste(A, collapse=" "))