rcountunique

Count number of occurences for each unique value

Let's say I have:

v = rep(c(1,2, 2, 2), 25)

Now, I want to count the number of times each unique value appears. unique(v) returns what the unique values are, but not how many they are. 

> unique(v)
[1] 1 2

I want something that gives me 

length(v[v==1])
[1] 25
length(v[v==2])
[1] 75

but as a more general one-liner :) Something close (but not quite) like this:

#<doesn't work right> length(v[v==unique(v)])
Solution

  • Perhaps table is what you are after?

    dummyData = rep(c(1,2, 2, 2), 25)

table(dummyData)
# dummyData
#  1  2 
# 25 75

## or another presentation of the same data
as.data.frame(table(dummyData))
#    dummyData Freq
#  1         1   25
#  2         2   75