How to use custom functions in mutate (dplyr)?

Question

I\'m rewriting all my code using dplyr, and need help with mutate / mutate_at function. All I need is to apply custom function to two columns in my table. Ideally, I would r

Answer 1

Your problem seems to be binom.test instead of dplyr, binom.test is not vectorized, so you can not expect it work on vectors; You can use mapply on the two columns with mutate:

table %>% 
    mutate(Ratio = mapply(function(x, y) binom.test.p(c(x,y)), 
                          ref_SG1_E2_1_R1_Sum, 
                          alt_SG1_E2_1_R1_Sum))

#  geneId ref_SG1_E2_1_R1_Sum alt_SG1_E2_1_R1_Sum Ratio
#1      a                  10                  10     1
#2      b                  20                  20     1
#3      c                  10                  10     1
#4      d                  15                  15     1

---

As for the last one, you need mutate_at instead of mutate:

table %>%
      mutate_at(.vars=c(2:3), .funs=funs(sum=sum(.)))