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Add RIVM graph theme to ggplot object

Source: R/ro_gg_theme.R
ro_gg_theme.Rd

ro_gg_theme() is a custom ggplot2 theme designed to apply the RIVM style to your visualizations. It functions similarly to built-in ggplot2 themes like theme_minimal(). Wherever technically feasible, this theme adheres to the RIVM guidelines for data visualization. We use versioning to enable the user to inspect new theme changes and compare them side-by-side. version 1.0 is the first published version and ro_gg_theme(version = 1.0) corresponds to this version. We also offer the version 0.0, which was the 'work in progress' version of the theme when the official guidelines were not published yet.

Usage

ro_gg_theme(
  base_size = 12,
  base_family = "RijksoverheidSansWebText",
  flip = FALSE,
  version = "1.0"
)

Arguments

base_size

Integer. Default = 13. If you select version 1.0, base_size is transformed to base_size / 13 * 12 (default = 12).

base_family

Character. Default = "RijksoverheidSansWebText". Accepts system fonts. If RijksoverheidSansWebText is not installed, Verdana is used, then Arial, then the first font found on your system, whichever is installed first. Tip: you can check your available systemfonts with systemfonts::system_fonts()$family.

flip

Logical. When set to FALSE (default), graphs have a thick x-axis and horizontal grid lines. For certain types of graphs, such as those with horizontal bars, it may be necessary to 'flip' these elements. Setting flip to TRUE changes the style to include a thick y-axis and vertical grid lines. Note: flip is only available from version 1.0. If you set it to TRUE for version 0.0, it will be ignored.

version

Character. The theme version. Default = 1.0.

Value

ggplot theme object

Dependencies

RIVM style characteristics (version 1.0)

The following design elements from the RIVM style guide are incorporated into ro_gg_theme():

  • Background and Layout:

    • The background color for all plot elements is white.

    • The y-axis is hidden, while the x-axis is shown.

    • Major x-axis grid lines are hidden, major y-axis grid lines are shown, minor grid lines are hidden.

    • Titles (main, subtitle, caption, and facet) are aligned to the left of the plot area.

    • The x-axis title is aligned to the right of the plot area.

    • The legend is positioned at the bottom and aligned to the left of the plot area.

    • Margins around the plot have been increased to ensure all text elements have enough space.

  • Colors:

    • Titles (main, subtitle, legend, facet): ro_color("donkerblauw")

    • Caption: "#505050"

    • Text and axis lines: ro_color("grijs_7") and default base_line_size.

    • Grid lines: ro_color("grijs_3")

  • Text:

    • All text elements are proportionally sized relative to base_size:

    • Main title: ro_color("donkerblauw"), bold and 1.42 × base_size.

    • Subtitle: ro_color("donkerblauw") and 1.17 × base_size.

    • Other titles: ro_color(donkerblauw) and 1.08 x base_size.

    • Caption: "#505050" and default base_size.

    • Legend text: ro_color("grijs_7") and 1.08 x base_size.

    • Other text: ro_color("grijs_7") and default base_size.

  • Grid and Axis Formatting:

    • All line elements are proportionally sized relative to base_line_size (base_size / 22):

    • Axis lines: ro_color("grijs_7") and default base_line_size.

    • Grid lines: ro_color("grijs_3") and 0.5 × base_line_size.

  • Other:

    • Legend keys are designed to be twice as wide as they are high.

    • Space between facets are twice the default size.

What are the differences between ro_gg_theme and the official RIVM style?

  • Font family: The official RIVM style uses the Rijksoverheid Sans font. This theme does not add the RO fonts to your device, but will use them if available. If the RO font is not available, Verdana is used, then Arial, then the first font found on your system, whichever is installed first (see ro_check_if_font_available).

  • Y-axis title alignment: The official RIVM style rotates the y-axis title horizontally and aligns it to the top of the plot area, which ggplot2 currently doesn't support. As a result, y-axis alignment is left to the user.

  • X-axis ticks: The official RIVM style positions x-axis ticks between the bars of a barplot. Achieving this in ggplot2 would require manually calculating the exact tick positions, which is too specific and inconsistent to implement as part of a general theme.

Theme customization approach

There are two approaches for creating a custom ggplot2 theme: (1) modifying an existing theme using 'existing theme + theme(...)' and (2) fully replacing it with 'existing theme %+replace% theme()'.

For ro_gg_theme(), we chose the first approach ('existing theme + theme(...)').This method offers greater flexibility to users, making it easier to apply additional customization on top of the ro_gg_theme() defaults.

See also

  • To view RIVM colors, use ROvis.utils function ro_show_colors.

  • To access the hex color code of a specific color, use the ROvis.utils function ro_color.

  • To view more usage examples, refer to the ROvis website.

Other ggplot2: ro_gg_axis(), ro_gg_group_ticks(), ro_gg_plot(), ro_gg_remove_axis_gap(), ro_gg_save(), ro_gg_y_title()

Examples

if (FALSE) { # \dontrun{
#without theme
my_plot <- ggplot2::ggplot(data = datasets::mtcars, mapping = ggplot2::aes(x = wt, y = mpg)) +
  ggplot2::geom_point() +
  ggplot2::labs(title = "mtcars plot")

#with theme version 0.0
my_plot +
  ROvis.utils::ro_gg_theme(version = "0.0")

#with theme version 1.0 (default)
my_plot +
  ROvis.utils::ro_gg_theme()

# different y-axis alignment choices
# top-aligned
my_plot +
  ROvis.utils::ro_gg_theme() +
  ggplot2::theme(axis.title.y = element_text(hjust = 1))
# annotated text as y-axis
my_plot +
  ROvis.utils::ro_gg_theme() +
  ggplot2::theme(axis.title.y = element_blank()) +
  ggplot2::annotate("text", x = 0, y = 35.5, label = "mpg", color = ro_color("lintblauw"))

  } # }