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Automatically create lines at the turn of every year

Source: R/geom_vline_year.R
geom_vline_year.Rd

Determines turn of year dates based on the range of either the x or y axis of the ggplot.

  • geom_vline_year() draws vertical lines at the turn of each year

  • geom_hline_year() draws horizontal lines at the turn of each year

Usage

geom_vline_year(
  mapping = NULL,
  position = "identity",
  year_break = "01-01",
  break_type = c("day", "week", "isoweek", "epiweek"),
  just = NULL,
  ...,
  show.legend = NA
)

geom_hline_year(
  mapping = NULL,
  position = "identity",
  year_break = "01-01",
  break_type = c("day", "week", "isoweek", "epiweek"),
  just = NULL,
  ...,
  show.legend = NA
)

Arguments

mapping

Mapping created using ggplot2::aes(). Can be used to add the lines to the legend. E.g. aes(linetype = 'End of Year'). Cannot access data specified in ggplot2::ggplot(). Panels created by ggplot2::facet_wrap() or ggplot2::facet_grid() are available with aes(linetype = PANEL).

position

Position adjustment, either as a string, or the result of a call to a position adjustment function.

year_break

String specifying the month and day ("MM-DD") or week ("W01") of the year break . Defaults to: "01-01" for January 1. "Week" and "MM-DD" are converted automatically based on a leap year (366 days) which starts on Monday.

break_type

String specifying the type of break to use. Options are:

  • "day" (default): Line drawn based on the specified day for each visible year.

  • "week" or "isoweek": Line drawn based on the Monday of the specified week for each visible year. (e.g., "W01" for new year or "W40" for start of influenza season)

  • "epiweek": same as week, but the line is drawn one day earlier (Sunday).

just

Numeric offset in days (justification). Shifts the lines from the year break date. Defaults to -0.5 for day, which shifts the line by half a day so it falls between December 31 and January 1 by default. Defaults to -3.5 (i.e. half a week) for week, isoweek and epiweek.

...

Other arguments passed to layer. For example:

  • colour Colour of the line. Try: colour = "grey50"

  • linetype Linetype. Try: linetype = "dashed" or linetype = "dotted"

  • linewidth Width of the line.

  • alpha Transparency of the line. used to set an aesthetic to a fixed value.

show.legend

logical. Should this layer be included in the legends? NA, the default, includes if any aesthetics are mapped. FALSE never includes, and TRUE always includes.

Value

A ggplot2 layer that can be added to a plot.

See also

geom_epicurve(), ggplot2::geom_vline()

Examples

library(ggplot2)
set.seed(1)

plot_data_epicurve_imp <- data.frame(
  date = rep(as.Date("2023-12-01") + ((0:300) * 1), times = rpois(301, 0.5))
)

# Break type day
ggplot(plot_data_epicurve_imp, aes(x = date, weight = 2)) +
  geom_epicurve(date_resolution = "week") +
  geom_vline_year() +
  labs(title = "Epicurve Example") +
  scale_y_cases_5er() +
  scale_x_date(date_breaks = "4 weeks", date_labels = "W%V'%g") + # Correct ISOWeek labels week'year
  theme_bw()


# Break type week  
ggplot(plot_data_epicurve_imp, aes(x = date, weight = 2)) +
  geom_epicurve(date_resolution = "week") +
  geom_vline_year(break_type = "week") +
  labs(title = "Epicurve Example") +
  scale_y_cases_5er() +
  scale_x_date(date_breaks = "4 weeks", date_labels = "W%V'%g") + # Correct ISOWeek labels week'year
  theme_bw()