counting the number of values greater than 0 in R in multiple columns

Question

I have a dataset myDF in R with a the variables L1,L2,L3,L4. How can I get the number of observations in L2, L3, and L4 that area greater than 0?

I would like to use the

Answer 1

We can use

colSums(myDF[c("L2", "L3", "L4")] > 0)

Answer 2

I don't think colSums will give you the right answer since it doesn't counts the number of observations, but only sums the columns' values.

I think that this will give you what you want , I hope.

apply(myDF,2,function(x) sum(x > 0))