How to add a column giving the number of values >0 in each row to a table in R?

Question

I have a table containing data that looks somewhat like this:

treatment, species1, species2, ... 
A, 3, 4, ... 
B, 2, 5, ...

I want to calculat

Answer 1

Depending on how your table is stored (this should work directly if it is the result of table, but could need some tweaking if it is a data frame or other structure), but it could be as simple as:

newtable <- addmargins(mytable, 1, FUN = function(x) sum( x > 0 ) )