forest_theme: Forest plot default theme

In forestploter: Create a Flexible Forest Plot

Forest plot default theme

Description

Default theme for the forest plot. Other parameters can also be passed and will be forwarded to the corresponding elements of the forest plot.

forest_theme is superseded by forest_style, see the section below for how its arguments map onto the new functions.

• ci_* Control the graphical parameters of confidence intervals

• legend_* Control the graphical parameters of legend

• xaxis_* Control the graphical parameters of x-axis

• refline_* Control the graphical parameters of reference line

• vertline_* Control the graphical parameters of vertical line

• summary_* Control the graphical parameters of diamond shaped summary CI

• footnote_* Control the graphical parameters of footnote

• title_* Control the graphical parameters of title

• arrow_* Control the graphical parameters of arrow

See gpar for more details.

Usage

forest_theme(
  base_size = 12,
  base_family = "",
  ci_pch = 15,
  ci_col = "black",
  ci_alpha = 1,
  ci_fill = NULL,
  ci_lty = 1,
  ci_lwd = 1,
  ci_Theight = NULL,
  legend_name = "Group",
  legend_position = "right",
  legend_value = "",
  legend_gp = gpar(),
  legend_ncol = 1,
  legend_byrow = TRUE,
  xaxis_gp = gpar(),
  refline_gp = gpar(),
  vertline_lwd = 1,
  vertline_lty = "dashed",
  vertline_col = "grey20",
  summary_col = "#4575b4",
  summary_fill = summary_col,
  footnote_gp = gpar(),
  footnote_parse = TRUE,
  title_just = c("left", "right", "center"),
  title_gp = gpar(),
  arrow_type = c("open", "closed"),
  arrow_label_just = c("start", "end"),
  arrow_length = 0.05,
  arrow_gp = gpar(),
  xlab_adjust = c("refline", "center"),
  xlab_gp = gpar(),
  ...
)

Arguments

base_size	The size of text
base_family	The font family
ci_pch	Shape of the point estimation. It will be reused if the forest plot is grouped.
ci_col	Color of the CI. A vector of colors should be provided for a grouped forest plot. An internal color set will be used if not provided.
ci_alpha	Scalar value, alpha channel for transparency of the point estimate. A small vertical line will be added to mark the location of the point estimate if this is not equal to 1.
ci_fill	Fill color of the point estimation. A vector of colors should be provided for a grouped forest plot. If this is NULL (default), the value will be inherited from ci_col. This is only effective if ci_pch is within 15:25.
ci_lty	Line type of the CI. A vector of line types should be provided for a grouped forest plot.
ci_lwd	Line width of the CI. A vector of line widths should be provided for a grouped forest plot.
ci_Theight	A unit specifying the height of the T end of the CI. If set to NULL (default), no T end will be drawn.
legend_name	Title of the legend.
legend_position	Position of the legend, "right", "top", "bottom" or "none" to suppress the legend.
legend_value	Legend labels (expressions). A vector should be provided for a grouped forest plot. Defaults to "Group 1", "Group 2", ... if not provided.
legend_gp	gpar graphical parameters of legend, see gpar.
legend_ncol	integer; the number of columns, see legendGrob.
legend_byrow	logical indicating whether rows of the legend are filled first, see legendGrob.
xaxis_gp	gpar graphical parameters of x-axis, see gpar.
refline_gp	gpar graphical parameters of reference line, see gpar.
vertline_lwd	Line width for extra vertical line. A vector can be provided for each vertical line, and the values will be recycled if not enough values are given.
vertline_lty	Line type for extra vertical line. Works same as vertline_lwd.
vertline_col	Line color for the extra vertical line. Works same as vertline_lwd.
summary_col	Color for borders of the summary diamond shape.
summary_fill	Color for filling the summary diamond shape.
footnote_gp	gpar graphical parameters of footnote, see gpar.
footnote_parse	Parse footnote text (default).
title_just	The justification of the title, default is 'left'.
title_gp	gpar graphical parameters of title, see gpar.
arrow_type	Type of the arrow below x-axis, see arrow.
arrow_label_just	The justification of the arrow label relative to arrow. Control the arrow label to align to the starting point of the arrow "start" (default) or the ending point of the arrow "end".
arrow_length	The length of the arrow head, default is 0.05. See arrow.
arrow_gp	gpar graphical parameters of arrow, see gpar.
xlab_adjust	Control the alignment of xlab to reference line (default) or center of the x-axis.
xlab_gp	gpar graphical parameters of xlab, see gpar.
...	Other parameters passed to table. See tableGrob for details.

Value

A list.

Moving to forest_style()

forest_style takes one gpar for each part of the plot, and the text of the legend is set with set_labs. Themes created with forest_theme still work: give them to the style argument of forest or to set_style.

• base_size, base_family, ci_pch, xlab_adjust, title_just, arrow_type, arrow_length, arrow_label_just, legend_position, legend_ncol, legend_byrow: the same arguments of forest_style.

• ci_col, ci_fill, ci_lty, ci_lwd, ci_alpha: forest_style(ci = gpar(col, fill, lty, lwd, alpha)).

• ci_Theight: forest_style(ci_t_height).

• summary_col, summary_fill: forest_style(summary = gpar(col, fill)).

• vertline_lwd, vertline_lty, vertline_col: forest_style(vline = gpar(lwd, lty, col)).

• refline_gp: forest_style(ref_line).

• xaxis_gp, xlab_gp, title_gp, footnote_gp, arrow_gp, legend_gp: the arguments of forest_style without _gp, e.g. forest_style(title = gpar(col = "red")).

• footnote_parse: forest_style(parse), which also applies to the title, x-axis labels, arrow labels and legend labels.

• legend_name, legend_value: legend_title and legend_labels of set_labs.

• The fill of core and colhead, e.g. core = list(bg_params = list(fill = "white")): forest_style(body = gpar(fill = "white")) and forest_style(header = gpar(fill = "white")).

• Other table settings in ...: passed to ... of forest_style in the same way.

See Also

tableGrob forest textGrob gpar arrow segmentsGrob linesGrob pointsGrob legendGrob

forestploter documentation built on Oct. 1, 2026, 1:08 a.m.