santoku - a visual introduction

Santoku

A Japanese kitchen knife.

{santoku}

An R package for cutting data.

Some data

head(pts)

##      x   y
## 1 1041 395
## 2 1283 310
## 3 1122 265
## 4 1383 402
## 5  433 331
## 6  538 304

x <- pts$x

Some data

plot_the_fish()

chop()

chop() is a replacement for base R’s cut() function.

chop()

chop(x, c(300, 600, 900))

extend = FALSE

chop(x, c(300, 600, 900), extend = FALSE)

Chopping by a single value

chop(x, c(300, 500, 500, 800))

chop_width()

Chops fixed-width intervals

chop_width(x, width = 200)

chop_evenly()

Chops groups equal-width intervals

chop_evenly(x, groups = 5)

chop_equally()

Chops intervals with an equal number of elements

chop_equally(x, groups = 5)

chop_n()

Chops intervals with a fixed number of elements

• The last group may have fewer elements

chop_n(x, 100)

Summary

chop_quantiles()

chop_quantiles(x, c(0.05, 0.25, 0.5, 0.75, 0.95)

chop_mean_sd()

chop_mean_sd(x)

Quick tables

tab(x, c(300, 600, 900))

## x
##   [70, 300)  [300, 600)  [600, 900] (900, 1393] 
##          10          52          44         138

tab_mean_sd(x)

## x
## [-3 sd, -2 sd) [-2 sd, -1 sd)  [-1 sd, 0 sd)   [0 sd, 1 sd)   [1 sd, 2 sd) 
##              5             54             48             80             57

Changing labels

You need one more labels than breaks:

chop(x, c(300, 600, 900), labels = LETTERS[1:4])

Changing labels

Not sure how many intervals you will have?

Use a lbl_* function.

chop_width(x, 200, labels = lbl_seq())

Changing labels

Not sure how many intervals you will have?

Use a lbl_* function.

chop_width(x, 200, labels = lbl_seq("(i)"))

Changing labels

Not sure how many intervals you will have?

Use a lbl_* function.

chop_width(x, 200, labels = lbl_dash())

Left-closed and right-closed

Breaks are closed on the left by default.

chop(x, c(200, 500, 800))

Left-closed and right-closed

For right-closed breaks use brk_right():

chop(x, brk_right(c(200, 500, 800)))

Errors

Happy chopping!

https://hughjonesd.github.io/santoku

devtools::install_github("hughjonesd/santoku")