win_over: Generate SQL expression for window functions
Description
win_over() makes it easy to generate the window function specification.
win_absent(), win_rank(), win_recycled(), and win_cumulative()
provide helpers for constructing common types of window functions.
win_current_group() and win_current_order() allow you to access
the grouping and order context set up by group_by() and arrange().
Usage
win_over(expr, partition = NULL, order = NULL, frame = NULL)
win_rank(f)
win_recycled(f)
win_cumulative(f)
win_absent(f)
win_current_group()
win_current_order()
Arguments
expr
The window expression
order
Variables to order by
frame
A numeric vector of length two defining the frame.