vector (or factor)
(x <- swiss$Education[1:20])
sort(x)
sort(x, partial = c(10, 15))
Partial sorting in R is different with that in Wikipedia.
A detailed introduction on subsetting is seen in Hadley Wickham’s Advanced R.
The three subsetting operators. The six types of subsetting. Important differences in behaviour for different objects (e.g., vectors, lists, factors, matrices, and data frames).
Benjamin on Stack Overflow answered the question 1 of the comparison between subset() and dplyr::filter().
They are, indeed, producing the same result, and they are very similar in concept.