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
              
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