santoku is a versatile cutting tool for R. It provides chop(), a
replacement for base::cut().
Install from r-universe:
install.packages("santoku", repos = c("https://hughjonesd.r-universe.dev",
"https://cloud.r-project.org"))
Or get the development version from GitHub:
# install.packages("remotes")
remotes::install_github("hughjonesd/santoku")
santoku is no longer on CRAN, though old versions are still available from their archive. I have no plans to change this.
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, and units.
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.
It’s easy to label intervals: use names for your breaks vector, or use
a lbl_* function to create 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.
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] [0.8347, 0.9347) [0.9347, 1.035] [0.2347, 0.3347) [0.7347, 0.8347)
#> [5] [0.6347, 0.7347) [0.4347, 0.5347) [0.7347, 0.8347) [0.1347, 0.2347)
#> [9] [0.6347, 0.7347) [0.6347, 0.7347)
#> 7 Levels: [0.1347, 0.2347) [0.2347, 0.3347) ... [0.9347, 1.035]
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
For more information, see the vignette.