mutate a new column on original df with quantiles?

Question

e.g.

diamonds$carat %>% quantile(probs = seq(0.1:1, by = 0.05))
 10%  15%  20%  25%  30%  35%  40%  45%  50%  55%  60%  65%  70%  75%  80%  85%  90%  95% 100% 
0.31 0.32 0.35 0.40 0.42 0.50 0.53 0.60 0.70 0.73 0.90 1.00 1.01 1.04 1.13 1.24 1.51 1.70 5.01 

Is there a clever 'tidyverse' way or otherwise to mutate a new column onto diamonds with the quantile from above that each observation belongs?

Answer 1

You can use cut.

data(diamonds, package="ggplot2")
library(dplyr)

diamonds %>%
  mutate(tile5=cut(carat, breaks=quantile(carat, probs=seq(0,1,0.05)), include=T, labels=F)) %>%
  select(carat, tile5)
# A tibble: 53,940 x 2
   carat tile5
   <dbl> <int>
 1 0.23      1
 2 0.21      1
 3 0.23      1
 4 0.290     1
 5 0.31      2
 6 0.24      1
 7 0.24      1
 8 0.26      1
 9 0.22      1
10 0.23      1
# ... with 53,930 more rows