Discretising numbers: cut_interval
Mix.install([
{:giggly, path: Path.join(__DIR__, "..")},
{:kino, "~> 0.19"}
])About this notebook
This notebook follows the examples on ggplot2's reference page for
cut_interval(), which covers
cut_number() and cut_width() too, in the order the page gives them. Each example shows
ggplot2's code first and then Giggly's. An example Giggly cannot draw yet keeps its ggplot2 code
and names what it is waiting for, so the page is also a list of what remains.
These functions turn a numeric vector into a factor whose levels are ranges of its values:
cut_interval() makes n ranges of equal width, cut_number() makes n ranges holding about the
same number of values each, and cut_width() makes ranges of a given width, placed by the centre or
the boundary of any one of them. Not in Giggly yet: cut_interval(), cut_number() and
cut_width(). Nor is a whole-column function in a mapping, such as cut_width(displ, 1): Giggly
applies an expression in each row, where these read the whole column.
Ranges of equal width
table(cut_interval(1:100, 10))
table(cut_interval(1:100, 11))
table() counts the values in each range: the numbers 1 to 100 cut into 10 ranges of equal
width, then into 11. Not in Giggly yet: cut_interval().
Ranges holding equal numbers of values
set.seed(1)
table(cut_number(runif(1000), 10))
With set.seed(1) fixing R's random numbers, runif(1000) draws 1,000 values between 0 and 1,
and cut_number() cuts them into 10 ranges holding about 100 values each. Not in Giggly yet:
cut_number().
Ranges of a given width
table(cut_width(runif(1000), 0.1))
table(cut_width(runif(1000), 0.1, boundary = 0))
table(cut_width(runif(1000), 0.1, center = 0))
table(cut_width(runif(1000), 0.1, labels = FALSE))
Each line draws 1,000 new random values and cuts them into ranges 0.1 wide. By default a boundary
falls at half the width; boundary = 0 puts one at 0 instead, center = 0 centres a range on 0,
and labels = FALSE gives each value its range's number rather than a factor. Not in Giggly yet:
cut_width().
