问题
Is there a way to do something like a cut() function for binning numeric values in a dplyr table? I'm working on a large postgres table and can currently either write a case statement in the sql at the outset, or output unaggregated data and apply cut(). Both have pretty obvious downsides... case statements are not particularly elegant and pulling a large number of records via collect() not at all efficient.
回答1:
Just so there's an immediate answer for others arriving here via search engine, the n-breaks form of cut is now implemented as the ntile function in dplyr:
> data.frame(x = c(5, 1, 3, 2, 2, 3)) %>% mutate(bin = ntile(x, 2))
x bin
1 5 2
2 1 1
3 3 2
4 2 1
5 2 1
6 3 2
来源：https://stackoverflow.com/questions/21714457/is-cut-style-binning-available-in-dplyr