Year Axis Scale for Historical Series — scale_x_year

A continuous x-axis scale for integer-year time series that picks break spacing according to the span of the data, so that century-long historical series (the norm in educabr2) get readable, evenly spaced year labels. The first and last years actually present in the series are always labelled, and any grid break that would collide with those extremes is dropped in their favour.

Usage

scale_x_year_educabr(years, ...)

Arguments

years: Numeric vector with the years actually plotted (typically data$year). Used to compute the span and anchor the first/last labels.
...: Additional arguments passed on to ggplot2::scale_x_continuous().

Value

A ggplot2 continuous position scale.

Details

Break spacing by span of the series: more than 60 years, every 20 years; 25 to 60 years, every 10 years; under 25 years, pretty() breaks. Labels are always four-digit years.

Examples

if (FALSE) { # \dontrun{
library(ggplot2)
library(educabr2)

df <- get_enrollment(level = "superior", network = "total",
                     modality = "total", indicator = "count")

ggplot(df, aes(x = year, y = value, colour = source)) +
  geom_line() +
  scale_x_year_educabr(df$year) +
  theme_educabr()
} # }