as_ternable: Create a ternable object

In prefviz: Visualizes Preference Data via Ternary Plots in Two and Higher Dimensions

Create a ternable object

Description

Creates a ternable object, which contains observation coordinates, simplex vertices, and edges necessary for building a ternary plot in both two and higher dimensions.

Usage

as_ternable(
  data,
  items = dplyr::everything(),
  group = NULL,
  order_by = NULL,
  decreasing = FALSE,
  na_method = c("drop_na", "drop_group"),
  ...
)

Arguments

data	A data frame containing the item (alternative) columns used to construct the ternary plot.
items	<tidy-select> Columns representing the items to be plotted as vertices of the simplex. Default is tidyselect::everything(), which selects all columns. Must select at least 3 columns. All columns must be non-negative and sum to 1.
group	Optional column name indicating the grouping variable. If specified, the data will be grouped by this variable. This is useful for creating paths between observations within each group.
order_by	Optional column name indicating the order variable. If specified, the data will be ordered by this variable. This is useful for creating paths between observations within each group.
decreasing	Logical. If TRUE, paths are ordered in decreasing order of order_by. If FALSE (default), ordering is increasing.
na_method	Character string specifying how to handle missing values in order_by. One of: "drop_na" (default): drop only rows where order_by is NA; "drop_group": drop entire groups that contain any NA in order_by.
...	Additional arguments (currently unused, reserved for future extensions).

Value

A ternable object (S3 class) containing:

data	: The validated and normalized data frame
data_coord	: Transformed coordinates for all observations
data_edges	: Edge connections for drawing paths between observations
simplex_vertices	: Vertex coordinates and labels for the simplex
simplex_edges	: Edge connections for drawing the simplex boundary
vertex_labels	: Labels of the vertices, same as names of the selected item columns

Examples

# Load and transform the dataset
prefviz::aecdop25_transformed

# Create the ternable object
tern <- as_ternable(prefviz::aecdop25_transformed, items = ALP:IND)
tern

prefviz documentation built on April 13, 2026, 5:07 p.m.