RidgePlot: Ridge Plot

In plotthis: High-Level Plotting Built Upon 'ggplot2' and Other Plotting Packages

Ridge Plot

Description

Ridge plot to illustrate the distribution of the data in different groups.

Usage

RidgePlot(
  data,
  x = NULL,
  in_form = c("long", "wide"),
  split_by = NULL,
  split_by_sep = "_",
  group_by = NULL,
  group_by_sep = "_",
  group_name = NULL,
  scale = NULL,
  keep_na = FALSE,
  keep_empty = FALSE,
  add_vline = NULL,
  vline_type = "solid",
  vline_color = TRUE,
  vline_width = 0.5,
  vline_alpha = 1,
  flip = FALSE,
  alpha = 0.8,
  theme = "theme_this",
  theme_args = list(),
  palette = "Paired",
  palcolor = NULL,
  title = NULL,
  subtitle = NULL,
  xlab = NULL,
  ylab = NULL,
  x_text_angle = 90,
  reverse = FALSE,
  facet_by = NULL,
  facet_scales = "fixed",
  facet_ncol = NULL,
  facet_nrow = NULL,
  facet_byrow = TRUE,
  aspect.ratio = 1,
  legend.position = "none",
  legend.direction = "vertical",
  combine = TRUE,
  nrow = NULL,
  ncol = NULL,
  byrow = TRUE,
  seed = 8525,
  axes = NULL,
  axis_titles = axes,
  guides = NULL,
  design = NULL,
  ...
)

Arguments

data	A data frame.
x	A character string specifying the column name of the data frame to plot for the x-axis.
in_form	A character string specifying the form of the data. Default is "long".
split_by	The column(s) to split data by and plot separately.
split_by_sep	The separator for multiple split_by columns. See split_by
group_by	Columns to group the data for plotting For those plotting functions that do not support multiple groups, They will be concatenated into one column, using group_by_sep as the separator
group_by_sep	The separator for multiple group_by columns. See group_by
group_name	A character string to name the legend of 'group_by', if 'legend.position' is not "none".
scale	A numeric value to scale the ridges. See also geom_density_ridges.
keep_na	A logical value or a character to replace the NA values in the data. It can also take a named list to specify different behavior for different columns. If TRUE or NA, NA values will be replaced with NA. If FALSE, NA values will be removed from the data before plotting. If a character string is provided, NA values will be replaced with the provided string. If a named vector/list is provided, the names should be the column names to apply the behavior to, and the values should be one of TRUE, FALSE, or a character string. Without a named vector/list, the behavior applies to categorical/character columns used on the plot, for example, the x, group_by, fill_by, etc.
keep_empty	One of FALSE, TRUE and "level". It can also take a named list to specify different behavior for different columns. Without a named list, the behavior applies to the categorical/character columns used on the plot, for example, the x, group_by, fill_by, etc. FALSE (default): Drop empty factor levels from the data before plotting. TRUE: Keep empty factor levels and show them as a separate category in the plot. "level": Keep empty factor levels, but do not show them in the plot. But they will be assigned colors from the palette to maintain consistency across multiple plots. Alias: levels
add_vline	A numeric vector or a named list of numeric values to add vertical lines to the plot. If a named list is provided, the names should match the levels of 'group_by'. If TRUE, the vertical lines will be added at the mean of each group.
vline_type	The type of line to draw for the vertical line.
vline_color	The color of the vertical line. If TRUE, the vertical lines will be colored according to the group colors.
vline_width	The width of the vertical line.
vline_alpha	The alpha value of the vertical line.
flip	A logical value. If TRUE, the plot will be flipped.
alpha	A numeric value specifying the transparency of the plot.
theme	A character string or a theme class (i.e. ggplot2::theme_classic) specifying the theme to use. Default is "theme_this".
theme_args	A list of arguments to pass to the theme function.
palette	A character string specifying the palette to use. A named list or vector can be used to specify the palettes for different split_by values.
palcolor	A character string specifying the color to use in the palette. A named list can be used to specify the colors for different split_by values. If some values are missing, the values from the palette will be used (palcolor will be NULL for those values).
title	A character string specifying the title of the plot. A function can be used to generate the title based on the default title. This is useful when split_by is used and the title needs to be dynamic.
subtitle	A character string specifying the subtitle of the plot.
xlab	A character string specifying the x-axis label.
ylab	A character string specifying the y-axis label.
x_text_angle	A numeric value specifying the angle of the x-axis text.
reverse	A logical value. If TRUE, reverse the order of the groups on the y-axis.
facet_by	A character string specifying the column name of the data frame to facet the plot. Otherwise, the data will be split by split_by and generate multiple plots and combine them into one using patchwork::wrap_plots
facet_scales	Whether to scale the axes of facets. Default is "fixed" Other options are "free", "free_x", "free_y". See ggplot2::facet_wrap
facet_ncol	A numeric value specifying the number of columns in the facet. When facet_by is a single column and facet_wrap is used.
facet_nrow	A numeric value specifying the number of rows in the facet. When facet_by is a single column and facet_wrap is used.
facet_byrow	A logical value indicating whether to fill the plots by row. Default is TRUE.
aspect.ratio	A numeric value specifying the aspect ratio of the plot.
legend.position	A character string specifying the position of the legend. if waiver(), for single groups, the legend will be "none", otherwise "right".
legend.direction	A character string specifying the direction of the legend.
combine	Whether to combine the plots into one when facet is FALSE. Default is TRUE.
nrow	A numeric value specifying the number of rows in the facet.
ncol	A numeric value specifying the number of columns in the facet.
byrow	A logical value indicating whether to fill the plots by row.
seed	The random seed to use. Default is 8525.
axes	A string specifying how axes should be treated. Passed to patchwork::wrap_plots(). Only relevant when split_by is used and combine is TRUE. Options are: 'keep' will retain all axes in individual plots. 'collect' will remove duplicated axes when placed in the same run of rows or columns of the layout. 'collect_x' and 'collect_y' will remove duplicated x-axes in the columns or duplicated y-axes in the rows respectively.
axis_titles	A string specifying how axis titltes should be treated. Passed to patchwork::wrap_plots(). Only relevant when split_by is used and combine is TRUE. Options are: 'keep' will retain all axis titles in individual plots. 'collect' will remove duplicated titles in one direction and merge titles in the opposite direction. 'collect_x' and 'collect_y' control this for x-axis titles and y-axis titles respectively.
guides	A string specifying how guides should be treated in the layout. Passed to patchwork::wrap_plots(). Only relevant when split_by is used and combine is TRUE. Options are: 'collect' will collect guides below to the given nesting level, removing duplicates. 'keep' will stop collection at this level and let guides be placed alongside their plot. 'auto' will allow guides to be collected if a upper level tries, but place them alongside the plot if not.
design	Specification of the location of areas in the layout, passed to patchwork::wrap_plots(). Only relevant when split_by is used and combine is TRUE. When specified, nrow, ncol, and byrow are ignored. See patchwork::wrap_plots() for more details.
...	Additional arguments.

Value

A ggplot object or wrap_plots object or a list of ggplot objects. If no split_by is provided, a single plot (ggplot object) will be returned. If 'combine' is TRUE, a wrap_plots object will be returned. If 'combine' is FALSE, a list of ggplot objects will be returned.

Examples

set.seed(8525)
data <- data.frame(
   x = c(rnorm(250, -1), rnorm(250, 1)),
   group = factor(rep(c("A", NA, LETTERS[3:5]), each = 100), levels = LETTERS[1:6])
)
RidgePlot(data, x = "x")  # fallback to a density plot
RidgePlot(data, x = "x", add_vline = 0, vline_color = "black")
RidgePlot(data, x = "x", group_by = "group")
RidgePlot(data, x = "x", group_by = "group",
   keep_na = TRUE, keep_empty = TRUE)
RidgePlot(data, x = "x", group_by = "group", reverse = TRUE)
RidgePlot(data, x = "x", group_by = "group",
   add_vline = TRUE, vline_color = TRUE, alpha = 0.7)
RidgePlot(data, x = "x", facet_by = "group",
   keep_na = TRUE, keep_empty = TRUE)

# wide form
data_wide <- data.frame(
   A = rnorm(100),
   B = rnorm(100),
   C = rnorm(100),
   D = rnorm(100),
   E = rnorm(100),
   group = sample(letters[1:4], 100, replace = TRUE)
)
RidgePlot(data_wide, group_by = LETTERS[1:5], in_form = "wide")
RidgePlot(data_wide, group_by = LETTERS[1:5], in_form = "wide", facet_by = "group")
RidgePlot(data_wide, group_by = LETTERS[1:5], in_form = "wide", split_by = "group",
   palette = list(a = "Reds", b = "Blues", c = "Greens", d = "Purples"))

plotthis documentation built on Feb. 7, 2026, 1:07 a.m.