Windowed rank functions.
Six variations on ranking functions, mimicing the ranking
functions described in SQL2003. They are currently
implemented using the built in
rank function, and
are provided mainly as a convenience when converting
between R and SQL. All ranking functions map smallest
inputs to smallest outputs. Use
reverse the direction..
- a vector of values to rank
- number of groups to split up into.
row_number: equivalent to
rank(ties.method = "first")
min_rank: equivalent to
rank(ties.method = "min")
min_rank, but with no gaps between ranks
percent_rank: a number between 0 and 1 computed by rescaling
min_rankto [0, 1]
cume_dist: a cumulative distribution function. Proportion of all values less than or equal to the current rank.
ntile: a rough rank, which breaks the input vector into
x <- c(5, 1, 3, 2, 2) row_number(x) min_rank(x) dense_rank(x) percent_rank(x) cume_dist(x) ntile(x, 2) ntile(runif(100), 10)