Concatenate strings by group with dplyr for multiple columns [duplicate]

Answer 1

using dplyr, you can try:

dft %>%
  group_by(Sample) %>%
  summarise_each(funs( toString(unique(.))))

which gives:

# A tibble: 3 × 5
  Sample   group   Gene1 Gene2    Gene3
   <chr>   <chr>   <chr> <chr>    <chr>
1      A    1, 2    a, b    NA       NA
2      B       1      NA     c       NA
3      C 1, 2, 3 a, b, c    NA d, e, NA

Edit: @Axeman had the right idea with using na.omit(.) to get rid of null values

Answer 2

For these purposes, there are the summarise_all, summarise_at, and summarise_if functions. Using summarise_all:

df %>%
  group_by(Sample) %>%
  summarise_all(funs(paste(na.omit(.), collapse = ",")))

# A tibble: 3 × 5
  Sample group Gene1 Gene2 Gene3
   <chr> <chr> <chr> <chr> <chr>
1      A   1,2   a,b            
2      B     1           c      
3      C 1,2,3 a,b,c         d,e