Nested if-else loops in R

Question

I have a data frame named \"crimes\" which contains a \"pre_rate\" column that denotes the crime rate before a certain law is implemented. I would like to put each rate in a

Answer 1

If your data does not contain gaps, and you just want an index, you can use .bincode:

crimes$rate_category <- .bincode(crimes$pre_rate,
                                 breaks = c(-Inf, 1, 2, 3, 4, Inf))

If you want specific values for each interval, you can use a rolling join via the data.table package:

library(magrittr)
library(data.table)

rate_category_by_pre_rate <- 
  data.table(rate_category = c("foo", "bar", "foobar", "baz", "foobie"),
             pre_rate = c(1, 2, 3, 4, 11)) %>%
  setkey(pre_rate)

crimes %>%
  as.data.table %>%
  setkey(pre_rate) %>%
  rate_category_by_pre_rate[., roll = -Inf]

#>    rate_category pre_rate
#> 1:           foo     0.27
#> 2:           bar     1.91
#> 3:        foobar     2.81
#> 4:           baz     3.21
#> 5:        foobie     4.80

However, in your case, you may only need ceiling (i.e. round-up the value of pre_rate and cap it at 5:

crimes$rate_category <- pmin(ceiling(crimes$pre_rate), 5)

#>   pre_rate rate_category
#> 1     0.27             1
#> 2     1.91             2
#> 3     2.81             3
#> 4     3.21             4
#> 5     4.80             5