BarPlotGrouped: Bar plot with groups
In plotthis: High-Level Plotting Built Upon 'ggplot2' and Other Plotting Packages

BarPlotGrouped

R Documentation

Bar plot with groups

Description

Core implementation for drawing a grouped bar plot. Each x-axis category is split into side-by-side (dodge) or stacked bars according to the group_by variable. This is the grouped code path dispatched by BarPlotAtomic when group_by is provided.

Usage

BarPlotGrouped(
  data,
  x,
  x_sep = "_",
  y = NULL,
  scale_y = FALSE,
  flip = FALSE,
  group_by,
  group_by_sep = "_",
  group_name = NULL,
  theme = "theme_this",
  theme_args = list(),
  palette = "Paired",
  palcolor = NULL,
  palreverse = FALSE,
  label = NULL,
  label_nudge = 0.02,
  label_fg = "black",
  label_size = 4,
  label_bg = "white",
  label_bg_r = 0.1,
  add_bg = FALSE,
  bg_palette = "stripe",
  bg_palcolor = NULL,
  bg_alpha = 0.2,
  alpha = 1,
  x_text_angle = 0,
  aspect.ratio = 1,
  add_line = NULL,
  line_color = "red2",
  line_width = 0.6,
  line_type = 2,
  line_name = NULL,
  add_trend = FALSE,
  trend_color = "black",
  trend_linewidth = 1,
  trend_ptsize = 2.5,
  position = "auto",
  position_dodge_preserve = "total",
  y_min = NULL,
  y_max = NULL,
  legend.position = "right",
  legend.direction = "vertical",
  title = NULL,
  subtitle = NULL,
  xlab = NULL,
  ylab = NULL,
  keep_na = FALSE,
  keep_empty = FALSE,
  expand = waiver(),
  width = 0.8,
  facet_by = NULL,
  facet_scales = "fixed",
  ...
)

Arguments

`data`	A data frame.
`x`	A character string specifying the column name of the data frame to plot for the x-axis.
`x_sep`	A character string to join multiple `x` columns. Default `"_"`.
`y`	A character string specifying the column name of the data frame to plot for the y-axis.
`scale_y`	A logical value. When `TRUE`, y-values are scaled to proportions within each x position so that each position's total is 100\ Only applicable when `position = "stack"`.
`flip`	Logical; if `TRUE`, swap the x and y axes.
`group_by`	A character vector of column name(s) to group the bars by. Each unique combination becomes a separate bar segment. Multiple columns are concatenated with `group_by_sep`. Required.
`group_by_sep`	A character string to separate concatenated `group_by` columns. Default `"_"`.
`group_name`	A character string for the group fill legend title. When `NULL`, the `group_by` column name is used.
`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).
`palreverse`	A logical value indicating whether to reverse the palette. Default is FALSE.
`label`	A column name (or `TRUE`) for text labels on bars. When `TRUE`, the y-axis values are labelled. When a column name, the values in that column are used.
`label_nudge`	A numeric value controlling the distance between labels and the bar top, expressed as a fraction of the data range.
`label_fg`	A character string specifying the label text colour.
`label_size`	A numeric value specifying the label text size.
`label_bg`	A character string specifying the label background colour.
`label_bg_r`	A numeric value specifying the label background corner radius.
`add_bg`	Logical; add alternating background stripes behind the bars.
`bg_palette`	Palette for the background stripes.
`bg_palcolor`	Custom colours for the background stripes.
`bg_alpha`	Alpha transparency for the background stripes.
`alpha`	A numeric value specifying the transparency of the plot.
`x_text_angle`	A numeric value specifying the angle of the x-axis text.
`aspect.ratio`	A numeric value specifying the aspect ratio of the plot.
`add_line`	A numeric y-intercept for a horizontal reference line.
`line_color`	Colour of the reference line.
`line_width`	Width of the reference line.
`line_type`	Linetype of the reference line (e.g., 1 = solid, 2 = dashed).
`line_name`	Legend name for the reference line.
`add_trend`	Logical; add a trend line and points connecting the bar tops.
`trend_color`	Colour of the trend line.
`trend_linewidth`	Width of the trend line.
`trend_ptsize`	Size of the trend line points.
`position`	A character string specifying the bar layout: `"auto"` (default: dodge when `\le`5 groups, stack otherwise), `"dodge"` (side-by-side), or `"stack"` (stacked on top of each other).
`position_dodge_preserve`	A character string passed to `position_dodge2()`: `"total"` preserves the overall bar group width; `"single"` preserves individual bar widths.
`y_min`, `y_max`	Numeric limits for the y-axis (or x-axis when flipped).
`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.
`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.
`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`
`expand`	The values to expand the x and y axes. It is like CSS padding. When a single value is provided, it is used for both axes on both sides. When two values are provided, the first value is used for the top/bottom side and the second value is used for the left/right side. When three values are provided, the first value is used for the top side, the second value is used for the left/right side, and the third value is used for the bottom side. When four values are provided, the values are used for the top, right, bottom, and left sides, respectively. You can also use a named vector to specify the values for each side. When the axis is discrete, the values will be applied as 'add' to the 'expansion' function. When the axis is continuous, the values will be applied as 'mult' to the 'expansion' function. See also https://ggplot2.tidyverse.org/reference/expansion.html
`width`	A numeric value specifying the bar width (0–1).
`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`
`...`	Additional arguments.

Value

A ggplot object with height and width attributes (in inches) attached.

Architecture

Column resolution — group_by, facet_by, x, and y are validated and transformed via check_columns.
Count aggregation — when y = NULL, the count of observations per (x, group_by, facet_by) combination is computed. Factor levels are preserved.
Proportion scaling — when scale_y = TRUE, y-values are divided by the sum within each (x, facet_by) group so that each x position stacks to 100\
Position resolution — position = "auto" chooses "dodge" for \le5 groups or "stack" for >5 groups. Explicit "dodge" and "stack" are also accepted.
Expand calculation — for stacked bars, expansion is computed from y-range and label presence. For dodged bars, expansion is minimal. The norm_expansion() utility normalises the final expansion vector.
Colour mapping — palette_this() assigns per-group colours. The fill scale drop argument is controlled by keep_empty_group.
Labels — when label is set:
- For stacked bars, cumulative label positions are computed so each label is centred within its segment.
- For dodged bars, labels are nudged above/below the bar top by label_nudge × the data range.
- geom_text_repel() is used for automatic overlap avoidance.
Trend line — when add_trend = TRUE, lines connect bar tops. When trend_color is NULL, each group gets its own coloured line; otherwise a single colour is used.
Horizontal reference line — add_line draws a geom_hline() at the specified y-value.
Dimension calculation — width accounts for the number of x categories × number of groups (dodge) or just x categories (stack). calculate_plot_dimensions() adjusts for flip and legend metrics.
Coordinate transform — coord_flip() or coord_cartesian() with y_min / y_max.