dplyr n_distinct with condition

Question

Using dplyr to summarise a dataset, I want to call n_distinct to count the number of unique occurrences in a column. However, I also want to do another summarise() for all uniqu

Answer 1

We can also use aggregate from base R

 aggregate(cbind(count=A)~B, a, FUN=function(x) length(unique(x)))
 #  B count
 #1 N 1
 #2 Y 2

Based on the OP's expected output

 data.frame(count=length(unique(a$A)), 
            count_BisY = length(unique(a$A[a$B=="Y"])))