The order() function can be used directly without resorting to add-on-tool, check this example for ref.
R> dd[with(dd, order(-z, f)), ]
b x y z
4 Low C 8 2
2 Med D 4 1
1 Hi A 7 1
3 Hi A 8 1
Alternatively one can use dplyr or data.table solutions, If there’s importance of no-dependency us base::order