% Generated by roxygen2: do not edit by hand
% Please edit documentation in R/radarplot.R
\name{RadarPlot}
\alias{RadarPlot}
\alias{SpiderPlot}
\title{Radar plot / Spider plot}
\usage{
RadarPlot(
  data,
  x,
  x_sep = "_",
  group_by = NULL,
  group_by_sep = "_",
  y = NULL,
  group_name = NULL,
  groups = NULL,
  scale_y = c("group", "global", "x", "none"),
  y_min = 0,
  y_max = NULL,
  y_nbreaks = 4,
  bg_color = "grey80",
  bg_alpha = 0.1,
  fill = TRUE,
  linewidth = 1,
  pt_size = 4,
  max_charwidth = 16,
  split_by = NULL,
  split_by_sep = "_",
  theme = "theme_this",
  theme_args = list(),
  palette = "Paired",
  palcolor = NULL,
  palreverse = FALSE,
  facet_by = NULL,
  facet_scales = "fixed",
  facet_ncol = NULL,
  facet_nrow = NULL,
  facet_byrow = TRUE,
  alpha = 0.2,
  aspect.ratio = 1,
  legend.position = waiver(),
  legend.direction = "vertical",
  keep_na = FALSE,
  keep_empty = FALSE,
  title = NULL,
  subtitle = NULL,
  seed = 8525,
  combine = TRUE,
  nrow = NULL,
  ncol = NULL,
  byrow = TRUE,
  axes = NULL,
  axis_titles = axes,
  guides = NULL,
  design = NULL,
  ...
)

SpiderPlot(
  data,
  x,
  x_sep = "_",
  group_by = NULL,
  group_by_sep = "_",
  y = NULL,
  group_name = NULL,
  groups = NULL,
  scale_y = c("group", "global", "x", "none"),
  y_min = 0,
  y_max = NULL,
  y_nbreaks = 4,
  bg_color = "grey80",
  bg_alpha = 0.1,
  fill = TRUE,
  linewidth = 1,
  pt_size = 4,
  max_charwidth = 16,
  split_by = NULL,
  split_by_sep = "_",
  theme = "theme_this",
  theme_args = list(),
  palette = "Paired",
  palcolor = NULL,
  palreverse = FALSE,
  facet_by = NULL,
  facet_scales = "fixed",
  facet_ncol = NULL,
  facet_nrow = NULL,
  facet_byrow = TRUE,
  alpha = 0.2,
  aspect.ratio = 1,
  legend.position = waiver(),
  legend.direction = "vertical",
  keep_na = FALSE,
  keep_empty = FALSE,
  title = NULL,
  subtitle = NULL,
  seed = 8525,
  combine = TRUE,
  nrow = NULL,
  ncol = NULL,
  byrow = TRUE,
  axes = NULL,
  axis_titles = axes,
  guides = NULL,
  design = NULL,
  ...
)
}
\arguments{
\item{data}{A data frame.}

\item{x}{A character string specifying the column name of the data frame to plot for the x-axis.}

\item{x_sep}{A character string used to join multiple \code{x}
columns.  Default \code{"_"}.  Ignored when \code{x} is a single
column.}

\item{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 \code{group_by_sep} as the separator}

\item{group_by_sep}{The separator for multiple group_by columns. See \code{group_by}}

\item{y}{A character string specifying the column name of the data frame to plot for the y-axis.}

\item{group_name}{A character string used as the colour/fill legend
title.  When \code{NULL}, the \code{group_by} column name is used.}

\item{groups}{A character vector of group values (in the
\code{group_by} column) to include in the plot.  When \code{NULL},
all groups are included.  This can control which groups appear and
their legend order.  Implies \code{keep_empty = FALSE} for the
\code{group_by} column: groups not present in the data are not
shown in the legend.}

\item{scale_y}{How should the radial axis be scaled?  Default is
\code{"group"}.  Options are \code{"group"}, \code{"global"},
\code{"x"}, and \code{"none"}.
\itemize{
\item{\code{"group"} — scaled to the fraction within each group.}
\item{\code{"global"} — scaled to the fraction of the total.}
\item{\code{"x"} — scaled to the fraction within each x-axis category.}
\item{\code{"none"} — raw counts or values, no scaling.}
}}

\item{y_min}{A numeric value setting the minimum of the radial
axis.  Default \code{0}.}

\item{y_max}{A numeric value setting the maximum of the radial
axis.  When \code{NULL}, the maximum data value is used.}

\item{y_nbreaks}{A numeric value for the number of breaks
(concentric grid lines) on the radial axis.  Default \code{4}.}

\item{bg_color}{A character string specifying the background fill
colour.  Default \code{"grey80"}.}

\item{bg_alpha}{A numeric value for the transparency of the
background fill.  Default \code{0.1}.}

\item{fill}{A logical value.  When \code{TRUE} (default), the data
polygons are filled with the group colour.  When \code{FALSE},
only outlines are drawn.}

\item{linewidth}{A numeric value for the width of the polygon
outline lines.  Default \code{1}.}

\item{pt_size}{A numeric value for the size of the data point
markers.  Default \code{4}.}

\item{max_charwidth}{A numeric value for the maximum character
width of x-axis labels before wrapping.  Default \code{16}.}

\item{split_by}{The column(s) to split the data by and produce
separate sub-plots.  Multiple columns are concatenated with
\code{split_by_sep}.}

\item{split_by_sep}{A character string to separate concatenated
\code{split_by} columns.  Default \code{"_"}.}

\item{theme}{A character string or a theme class (i.e. ggplot2::theme_classic) specifying the theme to use.
Default is "theme_this".}

\item{theme_args}{A list of arguments to pass to the theme function.}

\item{palette}{A character string specifying the palette to use.
A named list or vector can be used to specify the palettes for different \code{split_by} values.}

\item{palcolor}{A character string specifying the color to use in the palette.
A named list can be used to specify the colors for different \code{split_by} values.
If some values are missing, the values from the palette will be used (palcolor will be NULL for those values).}

\item{palreverse}{A logical value indicating whether to reverse the palette. Default is FALSE.}

\item{facet_by}{A character string specifying the column name of the data frame to facet the plot.
Otherwise, the data will be split by \code{split_by} and generate multiple plots
and combine them into one using \code{patchwork::wrap_plots}}

\item{facet_scales}{Whether to scale the axes of facets. Default is "fixed"
Other options are "free", "free_x", "free_y". See \code{ggplot2::facet_wrap}}

\item{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.}

\item{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.}

\item{facet_byrow}{A logical value indicating whether to fill the plots by row. Default is TRUE.}

\item{alpha}{A numeric value specifying the transparency of the plot.}

\item{aspect.ratio}{A numeric value specifying the aspect ratio of the plot.}

\item{legend.position}{A character string specifying the position of the legend.
if \code{waiver()}, for single groups, the legend will be "none", otherwise "right".}

\item{legend.direction}{A character string specifying the direction of the legend.}

\item{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 \code{x}, \code{group_by}, \code{fill_by}, etc.}

\item{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 \code{x}, \code{group_by}, \code{fill_by}, etc.
\itemize{
\item{\code{FALSE} (default): Drop empty factor levels from the data before plotting.}
\item{\code{TRUE}: Keep empty factor levels and show them as a separate category in the plot.}
\item{\code{"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: \code{levels}}
}}

\item{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.}

\item{subtitle}{A character string specifying the subtitle of the plot.}

\item{seed}{A numeric seed for reproducibility.  Passed to
\code{\link{validate_common_args}()}.}

\item{combine}{Logical; when \code{TRUE} (default), returns a
combined \code{patchwork} object.  When \code{FALSE}, returns a
named list of individual \code{ggplot} objects.}

\item{ncol, nrow}{Integer number of columns / rows for the combined
layout (passed to \code{\link[patchwork]{wrap_plots}}).}

\item{byrow}{Logical; fill the combined layout by row.  Default
\code{TRUE} (passed to \code{\link[patchwork]{wrap_plots}}).}

\item{axes}{A character string specifying how axes should be
treated across the combined layout (passed to
\code{\link[patchwork]{wrap_plots}}).}

\item{axis_titles}{A character string specifying how axis titles
should be treated across the combined layout.  Defaults to
\code{axes}.}

\item{guides}{A character string specifying how guides (legends)
should be collected across panels (passed to
\code{\link{combine_plots}()}).}

\item{design}{A custom layout design for the combined plot (passed
to \code{\link{combine_plots}()}).}

\item{...}{Additional arguments.}
}
\value{
A \code{ggplot} object (when \code{combine = TRUE} and
\code{split_by} is \code{NULL}), a \code{patchwork} object (when
\code{combine = TRUE} and \code{split_by} is provided), or a named
list of \code{ggplot} objects (when \code{combine = FALSE}), each
with \code{height} and \code{width} attributes in inches.

A \code{ggplot} object (when \code{combine = TRUE} and
\code{split_by} is \code{NULL}), a \code{patchwork} object (when
\code{combine = TRUE} and \code{split_by} is provided), or a named
list of \code{ggplot} objects (when \code{combine = FALSE}), each
with \code{height} and \code{width} attributes in inches.
}
\description{
Draws a radar chart (concentric circular grid) or spider chart
(polygonal grid) displaying multivariate data in a two-dimensional
polar coordinate system.  Each x-axis category is placed at an
evenly spaced angular position around the chart, and numeric values
are plotted along the radial axis.

The function supports \strong{count aggregation} (omit \code{y} to
plot observation counts), \strong{proportion scaling} (via
\code{scale_y}), per-group colour control, faceting, and splitting
into separate sub-plots via \code{split_by}.

\code{\link{SpiderPlot}} is an alias that renders the same data with
polygonal grid lines (spider chart style) by using
\code{polygon = TRUE}.

\code{SpiderPlot} is a variant of \code{\link{RadarPlot}} that renders the chart with
straight polygonal grid lines (spider chart) instead of concentric
circles.  Internally, it calls \code{\link{RadarPlotAtomic}} with
\code{polygon = TRUE} but is otherwise identical to
\code{\link{RadarPlot}} in behaviour and parameters.
}
\section{split_by Workflow}{

When \code{split_by} is provided:
\enumerate{
\item \code{\link{check_keep_na}()} and
\code{\link{check_keep_empty}()} normalise the
\code{keep_na} / \code{keep_empty} arguments for all
relevant columns (\code{x}, \code{split_by},
\code{group_by}, \code{facet_by}).
\item The \code{split_by} column is validated and its NA / empty
levels are processed via
\code{\link{process_keep_na_empty}()}.  It is then removed
from the per-column \code{keep_na} / \code{keep_empty}
lists.
\item The data frame is split by \code{split_by} (preserving
level order).  If \code{split_by} is \code{NULL}, the data
is wrapped in a single-element list with name \code{"..."}.
\item Per-split \code{palette}, \code{palcolor},
\code{legend.position}, and \code{legend.direction} are
resolved via \code{\link{check_palette}()},
\code{\link{check_palcolor}()}, and
\code{\link{check_legend}()}.
\item \code{\link{RadarPlotAtomic}()} is called for each split
with \code{polygon = FALSE}.  If \code{title} is a
function, it receives the split level name and can generate
dynamic titles.
\item Results are combined via \code{\link{combine_plots}()}
(when \code{combine = TRUE}) or returned as a named list.
}
}

\examples{
\donttest{
set.seed(8525)

# --- Radar chart with observation counts ---
data <- data.frame(
    x = factor(
        c(rep("A", 20), rep("B", 30), rep(NA, 30), rep("D", 40), rep("E", 50)),
        levels = LETTERS[1:5]
    ),
    group = factor(
        sample(c("G1", NA, "G3", "G4"), 170, replace = TRUE),
        levels = c("G1", "G2", "G3", "G4")
    )
)

# Basic radar chart
RadarPlot(data, x = "x")

# Keep NA and empty factor levels
RadarPlot(data, x = "x", keep_na = TRUE, keep_empty = TRUE)

# Custom background colour
RadarPlot(data, x = "x", bg_color = "lightpink")

# Raw counts (no proportion scaling)
RadarPlot(data, x = "x", scale_y = "none")

# Grouped by a variable
RadarPlot(data, x = "x", group_by = "group", keep_na = TRUE)

# Faceted by a variable
RadarPlot(data, x = "x", facet_by = "group")

# Spider chart variant (polygonal grid)
SpiderPlot(data, x = "x")
SpiderPlot(data, x = "x", group_by = "group")

# --- Radar chart with explicit y values ---
data <- data.frame(
    x = rep(LETTERS[1:5], 2),
    y = c(1, 3, 6, 4, 2, 5, 7, 8, 9, 10),
    group = rep(c("G1", "G2"), each = 5)
)

# Grouped radar with raw values
RadarPlot(data, x = "x", y = "y", scale_y = "none", group_by = "group")

# Faceted radar
RadarPlot(data, x = "x", y = "y", facet_by = "group")

# Split into separate sub-plots
RadarPlot(data, x = "x", y = "y", split_by = "group")

# Per-split palettes
RadarPlot(data, x = "x", y = "y", split_by = "group",
          palette = c(G1 = "Set1", G2 = "Paired"))
}
}
