Internal helper to add reference lines in an APC heatmap

Internal helper function to add reference lines in an APC heatmap (vertically, horizontally or diagonally). The function takes an existing list of ggplot objects, adds the specified reference lines in each plot and returns the edited ggplot list again. To be called from within plot_APCheatmap.

Usage

gg_addReferenceLines(
  gg_list,
  dimensions,
  plot_dat,
  markLines_list,
  markLines_displayLabels
)

Arguments

gg_list

Existing list of ggplot objects where the reference lines should be marked in each individual ggplot.

dimensions

Character vector specifying the two APC dimensions that should be visualized along the x-axis and y-axis. Defaults to c("period","age").

plot_dat

Dataset used for creating the heatmap.

markLines_list

Optional list that can be used to highlight the borders of specific age groups, time intervals or cohorts. Each element must be a numeric vector of values where horizontal, vertical or diagonal lines should be drawn (depends on which APC dimension is displayed on which axis). The list can maximally have three elements and must have names out of c("age","period","cohort").

markLines_displayLabels

Optional character vector defining for which dimensions the lines defined through markLines_list should be marked by a respective label. The vector should be a subset of c("age","period","cohort"), or NULL to suppress all labels. Defaults to c("age","period","cohort").