LinePlotSingle: Single-series line plot (internal)
In plotthis: High-Level Plotting Built Upon 'ggplot2' and Other Plotting Packages

LinePlotSingle

R Documentation

Single-series line plot (internal)

Description

Core implementation for drawing a single-series line plot. This is the workhorse behind LinePlotAtomic for ungrouped data – it takes a single data frame (no split_by support) and returns a ggplot object. Each x-axis category receives its own point and connecting line, with optional per-x coloring, error bars, highlighted points, and a horizontal reference line.

Usage

LinePlotSingle(
  data,
  x,
  y = NULL,
  fill_point_by_x = TRUE,
  color_line_by_x = TRUE,
  facet_by = NULL,
  add_bg = FALSE,
  bg_palette = "stripe",
  bg_palcolor = NULL,
  bg_alpha = 0.2,
  add_errorbars = FALSE,
  errorbar_width = 0.1,
  errorbar_alpha = 1,
  errorbar_color = "grey30",
  errorbar_linewidth = 0.75,
  errorbar_min = NULL,
  errorbar_max = NULL,
  errorbar_sd = NULL,
  highlight = NULL,
  highlight_size = pt_size - 0.75,
  highlight_color = "red2",
  highlight_alpha = 0.8,
  pt_alpha = 1,
  pt_size = 5,
  add_hline = FALSE,
  hline_type = "solid",
  hline_width = 0.5,
  hline_color = "black",
  hline_alpha = 1,
  line_type = "solid",
  line_width = 1,
  line_alpha = 0.8,
  theme = "theme_this",
  theme_args = list(),
  palette = "Paired",
  palcolor = NULL,
  palreverse = FALSE,
  x_text_angle = 0,
  aspect.ratio = 1,
  legend.position = "right",
  legend.direction = "vertical",
  title = NULL,
  subtitle = NULL,
  xlab = NULL,
  ylab = NULL,
  keep_empty = FALSE,
  keep_na = FALSE,
  ...
)

Arguments

`data`	A data frame.
`x`	A character string specifying the column name for the x-axis. Must be character or factor.
`y`	A character string specifying the numeric column for the y-axis. When `NULL`, the count of observations per x level is used.
`fill_point_by_x`	A logical value. When TRUE (default), points are filled by the x-axis categories using the palette. When FALSE, all points use the first palette colour.
`color_line_by_x`	A logical value. When TRUE (default), lines are coloured by the x-axis categories using the palette. When FALSE, all lines use the first palette colour.
`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`
`add_bg`	A logical value. When TRUE, alternating background stripes are drawn via `bg_layer()`. Default FALSE.
`bg_palette`	A character string specifying the palette for the background stripe colours. Default `"stripe"`.
`bg_palcolor`	A character vector of colours for the background stripes. When NULL (default), colours are derived from `bg_palette`.
`bg_alpha`	A numeric value in `[0, 1]` for the transparency of background stripes. Default 0.2.
`add_errorbars`	A logical value. When TRUE, error bars are added via `geom_errorbar()`. Requires `errorbar_sd` or `errorbar_min`/`errorbar_max`. Default FALSE.
`errorbar_width`	A numeric value for the width of the error bar caps. Default 0.1.
`errorbar_alpha`	A numeric value in `[0, 1]` for the transparency of error bars. Default 1.
`errorbar_color`	A character string for the colour of the error bars. When `"line"`, error bars are coloured the same as the lines (by x when `color_line_by_x = TRUE`, or single colour otherwise). Default `"grey30"`.
`errorbar_linewidth`	A numeric value for the line width of error bars. Default 0.75.
`errorbar_min`	A character string naming the column with the lower error bar bound. Ignored when `errorbar_sd` is provided.
`errorbar_max`	A character string naming the column with the upper error bar bound. Ignored when `errorbar_sd` is provided.
`errorbar_sd`	A character string naming the column with the standard deviation. When `errorbar_min` and `errorbar_max` are not provided, error bars are computed as y +/- `errorbar_sd`.
`highlight`	A vector of row indices, row names, a single string expression (e.g. `"y > 10"`) filtering rows to highlight, or TRUE to highlight all points. When NULL (default), no highlighting is applied.
`highlight_size`	A numeric value for the size of highlighted points. Defaults to `pt_size - 0.75`.
`highlight_color`	A character string for the colour of highlighted points. Default `"red2"`.
`highlight_alpha`	A numeric value in `[0, 1]` for the transparency of highlighted points. Default 0.8.
`pt_alpha`	A numeric value in `[0, 1]` for the transparency of points. Default 1.
`pt_size`	A numeric value for the point size. Default 5.
`add_hline`	A numeric value specifying the y-intercept of a horizontal reference line. When FALSE (default), no line is drawn.
`hline_type`	A character string specifying the line type of the horizontal reference line. Default `"solid"`.
`hline_width`	A numeric value for the width of the horizontal reference line. Default 0.5.
`hline_color`	A character string for the colour of the horizontal reference line. Default `"black"`.
`hline_alpha`	A numeric value in `[0, 1]` for the transparency of the horizontal reference line. Default 1.
`line_type`	A character string specifying the line type. Default `"solid"`.
`line_width`	A numeric value for the line width (in mm). Default 1.
`line_alpha`	A numeric value in `[0, 1]` for the transparency of the line. Default 0.8.
`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.
`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.
`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_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`
`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.
`...`	Additional arguments.

Value

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

Architecture

ggplot dispatch – selects gglogger::ggplot or ggplot2::ggplot based on getOption("plotthis.gglogger.enabled").
Column resolution – x (forced to factor), y, and facet_by are validated via check_columns.
Count aggregation – when y = NULL, the count of observations per x level (and facet) is computed and used as y.
Error bar validation – if add_errorbars = TRUE, checks that either errorbar_min/errorbar_max or errorbar_sd is provided.
NA / empty-level handling – process_keep_na_empty() applies keep_na and keep_empty policies.
Highlight parsing – highlight (indices, row names, expression string, or TRUE) is resolved to a subset of data rows.
Background layer – when add_bg = TRUE, alternating background stripes are drawn via bg_layer().
Horizontal reference line – when add_hline is numeric, a geom_hline() is added at that intercept.
Colour assignment – palette_this() assigns colours to all x-axis levels (including NA, defaulting to "grey80").
Line rendering – when color_line_by_x = TRUE, lines are coloured per x level via geom_line() with aes(color = x) and scale_color_manual(). Otherwise a single colour (the first palette entry) is used.
Error bars – when add_errorbars = TRUE, three colour modes are supported: follow the line colour ("line"), track x levels, or use a constant colour. Error bars are added via geom_errorbar().
Point rendering – when fill_point_by_x = TRUE, points are filled per x level via geom_point() with aes(fill = x) and scale_fill_manual(). Otherwise a single fill colour (first palette entry) is used.
Highlight overlay – an additional geom_point() layer draws highlighted rows in the specified colour and size.
Plot assembly – scale_x_discrete(), labs(), theme application, axis styling (angle, grid lines), and legend positioning.
Dimension calculation – calculate_plot_dimensions() computes height and width attributes (in inches) from x-axis category count, aspect ratio, and legend metrics.