Turning data to wide-form

Question

I have data in this format:

ID	risk	severity
1	A	green
1	A	amber
1	A	amber
1	B	amber
1	B	amber
1	B	amber
2	B	green
2	B	green
2	B	amber
2	C	green
2	C	red
2	C	red

I want to convert it to this format using dplyr on R-Studio:

ID	A	min_sev	max_sev	B	min_sev	max_sev	C	min_sev	max_sev
1	3	green	amber	3	amber	amber	0	NA	NA
2	0	NA	NA	3	green	amber	C	green	red

where,

min_sev = minimum severity

max_sev = maximum severity

Any help is appreciated, thanks in advance.

Answer 1

Good catch @r2evans, here is an even simpler solution with nest and unnest:

library(dplyr)
library(tidyr)

df %>%
  group_by(ID, risk) %>%
  summarise(min_sev = first(severity),
            max_sev = last(severity),
            count = n()) %>%
  group_by(ID, risk) %>%
  nest() %>%
  pivot_wider(names_from = risk, values_from = data) %>%
  unnest(cols = everything(), names_sep = "_")