# santoku

santoku is a versatile cutting tool for R. It provides `chop()`, a replacement for `base::cut()`.

Here are some advantages of santoku:

• By default, `chop()` always covers the whole range of the data, so you won’t get unexpected `NA` values.

• `chop()` can handle single values as well as intervals. For example, `chop(x, breaks = c(1, 2, 2, 3))` will create a separate factor level for values exactly equal to 2.

• `chop()` can handle many kinds of data, including numbers, dates and times.

• `chop_*` functions create intervals in many ways, using quantiles of the data, standard deviations, fixed-width intervals, equal-sized groups, or pretty intervals for use in graphs.

• `lbl_*` functions make it easy to label intervals: use interval notation like `[1, 2)`, dash notation like `1-2`, or arbitrary styles using `glue::glue()`.

• `tab_*` functions quickly chop data, then tabulate it.

These advantages make santoku especially useful for exploratory analysis, where you may not know the range of your data in advance.

## Examples

``library(santoku)``

`chop` returns a factor:

``````chop(1:5, c(2, 4))
#> [1] [1, 2) [2, 4) [2, 4) [4, 5] [4, 5]
#> Levels: [1, 2) [2, 4) [4, 5]``````

Include a number twice to match it exactly:

``````chop(1:5, c(2, 2, 4))
#> [1] [1, 2) {2}    (2, 4) [4, 5] [4, 5]
#> Levels: [1, 2) {2} (2, 4) [4, 5]``````

Use names in breaks for labels:

``````chop(1:5, c(Low = 1, Mid = 2, High = 4))
#> [1] Low  Mid  Mid  High High
#> Levels: Low Mid High``````

Or use `lbl_*` functions:

``````chop(1:5, c(2, 4), labels = lbl_dash())
#> [1] 1—2 2—4 2—4 4—5 4—5
#> Levels: 1—2 2—4 4—5``````

Chop into fixed-width intervals:

``````chop_width(runif(10), 0.1)
#>  [1] [0.58, 0.68)    [0.18, 0.28)    [0.68, 0.78)    [0.78, 0.88)
#>  [5] [0.18, 0.28)    [0.88, 0.98]    [0.28, 0.38)    [0.08001, 0.18)
#>  [9] [0.08001, 0.18) [0.08001, 0.18)
#> 7 Levels: [0.08001, 0.18) [0.18, 0.28) [0.28, 0.38) ... [0.88, 0.98]``````

Or into fixed-size groups:

``````chop_n(1:10, 5)
#>  [1] [1, 6)  [1, 6)  [1, 6)  [1, 6)  [1, 6)  [6, 10] [6, 10] [6, 10] [6, 10]
#> [10] [6, 10]
#> Levels: [1, 6) [6, 10]``````

Chop dates by calendar month, then tabulate:

``````library(lubridate)
#>
#> Attaching package: 'lubridate'
#> The following objects are masked from 'package:base':
#>
#>     date, intersect, setdiff, union

dates <- as.Date("2021-12-31") + 1:90

tab_width(dates, months(1), labels = lbl_discrete(fmt = "%d %b"))
#> 01 Jan—31 Jan 01 Feb—28 Feb 01 Mar—31 Mar
#>            31            28            31``````