Count number of unique values per row
count, r, row, unique
Solution
This `apply` function returns a vector of the number of unique values in each row:
apply(example, 1, function(x)length(unique(x)))
You can append it to your data.frame using on of the following two ways (and if you want to name that column as `count`):
example <- cbind(example, count = apply(example, 1, function(x)length(unique(x))))
or
example$count <- apply(example, 1, function(x)length(unique(x)))
Problem
I want to count the number of unique values per row. For instance with this data frame: ``` example <- data.frame(var1 = c(2,3,3,2,4,5), var2 = c(2,3,5,4,2,5), var3 = c(3,3,4,3,4,5)) ``` I want to add a column which counts the number of unique values per row; e.g. 2 for the first row (as there are 2's and 3's in the first row) and 1 for the second row (as there are only 3's in the second row). Does anyone know an easy code to do this? Up until now I only found code for counting the number of unique values per column.