Programmatic mappings: aes_

Mix.install([
  {:giggly, path: Path.join(__DIR__, "..")},
  {:kino, "~> 0.19"}
  ])

About this notebook

ggplot2's reference page for aes_(), which covers aes_string() and aes_q() too, has no examples, so this notebook says only what the page describes and where Giggly stands.

aes() captures the names it is given without evaluating them; aes_() and aes_string() build the same aesthetic mapping from inputs quoted explicitly, aes_string() from strings and aes_() from quoted calls or one-sided formulas, which made them easy to call from functions that build plots. aes_q() is another name for aes_(). All three are deprecated: ggplot2 now recommends aes() with the .data pronoun, aes(.data[[x_var]], .data[[y_var]]). A Giggly mapping is a plain map, %{x: :wt, y: :mpg}, given to Giggly.Plot.new/2 or to a layer; it names each column by an atom or a string, so a column name held in a variable goes into it as it is, and no function builds it. An expression is plain data too, a function and the values it is applied to in each row (Giggly.Mapping), so what aes_() quotes a function builds as it would any other value.