Dropping factors which levels have observations smaller than a specific value-R

Question

Let I have such data frame(df1) with factors:

factor1  factor2  factor3
-------  -------  -------
d        a         x
d        a         x
b        a                


        

Answer 1

We could use Filter

Filter(function(x) min(nlevels(x))>2, df1)

(based on the results in one of the upvoted posts)

Or it could be also

Filter(function(x) min(tabulate(x))>2, df1)