Type: Package
Title: Projection Visualization Plots for Dimensionally Reduced Data
Version: 0.1.1
Description: Creates visualization plots for 2D projected data including ellipse plots, Voronoi diagram plots, and combined ellipse-Voronoi plots. Designed to visualize class separation in dimensionally reduced data from techniques like principal component analysis (PCA), partial least squares discriminant analysis (PLS-DA) or others. For more details see Lotsch and Ultsch (2024) <doi:10.1016/j.imu.2024.101573>.
License: GPL-3
Encoding: UTF-8
Depends: R (≥ 3.5.0)
Imports: ggplot2, ggrepel, deldir
RoxygenNote: 7.2.0
NeedsCompilation: no
Packaged: 2025-06-07 15:00:40 UTC; joern
Author: Jorn Lotsch ORCID iD [aut, cre]
Maintainer: Jorn Lotsch <j.lotsch@em.uni-frankfurt.de>
Repository: CRAN
Date/Publication: 2025-06-19 19:20:14 UTC

Projection Visualization Plots for Dimensionally Reduced Data

Description

Creates visualization plots for 2D projected data including ellipse plots, Voronoi diagram plots, and combined ellipse-Voronoi plots. Designed to visualize class separation in dimensionally reduced data from techniques like principal component analysis (PCA), partial least squares discriminant analysis (PLS-DA) or others. For more details see Lotsch and Ultsch (2024) <doi:10.1016/j.imu.2024.101573>.

Details

The VoronoiBiomedPlot package provides functions for creating visualization plots of 2D projected data, particularly useful for biomedical data analysis and dimensionality reduction results.

The package includes two main functions:

These functions are designed to visualize class separation in dimensionally reduced data from techniques like PCA, PLS-DA, t-SNE, or other projection methods commonly used in biomedical research.

Voronoi tessellation divides the plot space into regions based on proximity to data points, providing an intuitive visualization of class boundaries and decision regions. Confidence ellipses show the distribution spread and correlation structure within each class.

Author(s)

Jorn Lotsch <j.lotsch@em.uni-frankfurt.de>

References

Lötsch, J. and A. Ultsch (2024). Comparative assessment of projection and clustering method combinations in the analysis of biomedical data. Informatics in Medicine Unlocked 50: 101573. https://www.sciencedirect.com/science/article/pii/S2352914824001291

See Also

Examples

# Load the iris dataset
data <- iris[, c("Sepal.Length", "Petal.Length", "Species")]

# Create comprehensive projection plots
plots <- create_projection_plots(
  data = data,
  class_column = "Species",
  legend_position = "bottom",
  add_grid_lines = FALSE
)

# Access individual plots
# plots$ellipse_plot
# plots$voronoi_plot
# plots$voronoi_plot_plus_ellipse

# Create standalone Voronoi plot
voronoi_plot <- create_voronoi_plot(
  data = data,
  class_column = "Species",
  legend_position = "bottom",
  add_grid_lines = FALSE
)

Create Projection Visualization Plots

Description

Creates three types of visualization plots for 2D projected data: ellipse plots, Voronoi diagram plots, and combined ellipse-Voronoi plots. The function is designed to visualize class separation in dimensionally reduced data.

Usage

create_projection_plots(
  data,
  class_column = NULL,
  alternative_class_column = NULL,
  coordinate_columns = NULL,
  case_labels = NULL,
  coord_names = c("Dim1", "Dim2"),
  title = NULL,
  show_labels = FALSE,
  ellipse_alpha = 0.1,
  voronoi_alpha = 0.3,
  point_size = 2,
  legend_position = "bottom",
  color_palette = NULL,
  add_grid_lines = FALSE,
  color_points = "primary",
  fill_voronoi = "primary",
  point_shape = "none",
  label_fontface = "plain",
  label_size = 3.88
)

Arguments

data

A data frame containing projected data. Must have at least 2 numeric columns. If more than 2 columns are provided, the first 2 are used as coordinates.

class_column

Character string specifying the column name containing class labels, or a vector of class labels. If NULL, all observations are treated as a single class. Default: NULL.

alternative_class_column

Character string specifying the column name containing alternative class labels, or a vector of alternative class labels. If NULL, uses class_column. Default: NULL.

coordinate_columns

Character vector of length 2 specifying the column names to use as coordinates. If NULL, uses the first two numeric columns. Default: NULL.

case_labels

Character vector of case labels for individual observations. If NULL, row numbers are used. Default: NULL.

coord_names

Character vector of length 2 specifying names for the coordinate axes. Default: c("Dim1", "Dim2").

title

Character string for plot title. If NULL, no title is added. Default: NULL.

show_labels

Logical indicating whether to show case labels on plots. Default: FALSE.

ellipse_alpha

Numeric value (0-1) for ellipse transparency. Default: 0.1.

voronoi_alpha

Numeric value (0-1) for Voronoi polygon transparency. Default: 0.3.

point_size

Numeric value for point size. Default: 2.

legend_position

Character string or numeric vector specifying legend position. Default: "bottom".

color_palette

Function or character vector for color palette. If NULL, uses ggplot2 default colors. Default: NULL.

add_grid_lines

Logical indicating whether to add dashed grid lines at origin. Default: FALSE.

color_points

Character string specifying which classification to use for point colors. Either "primary" (uses class_column) or "alternative" (uses alternative_class_column). Default: "primary".

fill_voronoi

Character string specifying which classification to use for Voronoi fill. Either "primary" (uses class_column) or "alternative" (uses alternative_class_column). Default: "primary".

point_shape

Character string specifying which classification to use for point shapes. Either "primary" (uses class_column), "alternative" (uses alternative_class_column), or "none" (no shape differentiation). Default: "none".

label_fontface

Character string specifying the font face for text labels. Options include "plain", "bold", "italic", "bold.italic". Default: "plain".

label_size

Numeric value specifying the size of text labels. Default: 3.88.

Details

The function creates visualizations for 2D projected data, particularly useful for displaying results from dimensionality reduction techniques like PCA, PLS-DA, or t-SNE.

Voronoi tessellation divides the plot space into regions based on proximity to data points, providing an intuitive visualization of class boundaries and decision regions.

Confidence ellipses show the distribution spread and correlation structure within each class.

Value

A list containing three ggplot objects:

ellipse_plot

Plot with confidence ellipses for each class

voronoi_plot

Plot with Voronoi tessellation regions

voronoi_plot_plus_ellipse

Combined plot with both Voronoi regions and ellipses

Examples

# Basic usage with iris dataset
data <- iris[, c("Sepal.Length", "Petal.Length", "Species")]
plots <- create_projection_plots(
  data = data,
  class_column = "Species",
  legend_position = "bottom",
  add_grid_lines = FALSE
)


Create Voronoi Projection Visualization Plot

Description

Creates a Voronoi tessellation visualization for 2D projected data, showing class separation through proximity-based regions.

Usage

create_voronoi_plot(
  data,
  class_column = NULL,
  alternative_class_column = NULL,
  coordinate_columns = NULL,
  case_labels = NULL,
  coord_names = c("Dim1", "Dim2"),
  title = NULL,
  show_labels = FALSE,
  voronoi_alpha = 0.3,
  point_size = 2,
  legend_position = "bottom",
  color_palette = NULL,
  add_grid_lines = FALSE,
  color_points = "primary",
  fill_voronoi = "primary",
  point_shape = "none",
  label_fontface = "plain",
  label_size = 3.88
)

Arguments

data

A data frame containing projected data. Must have at least 2 numeric columns. If more than 2 columns are provided, the first 2 are used as coordinates.

class_column

Character string specifying the column name containing class labels, or a vector of class labels. If NULL, all observations are treated as a single class. Default: NULL.

alternative_class_column

Character string specifying the column name containing alternative class labels, or a vector of alternative class labels. If NULL, uses class_column. Default: NULL.

coordinate_columns

Character vector of length 2 specifying the column names to use as coordinates. If NULL, uses the first two numeric columns. Default: NULL.

case_labels

Character vector of case labels for individual observations. If NULL, row numbers are used. Default: NULL.

coord_names

Character vector of length 2 specifying names for the coordinate axes. Default: c("Dim1", "Dim2").

title

Character string for plot title. If NULL, no title is added. Default: NULL.

show_labels

Logical indicating whether to show case labels on plots. Default: FALSE.

voronoi_alpha

Numeric value (0-1) for Voronoi polygon transparency. Default: 0.3.

point_size

Numeric value for point size. Default: 2.

legend_position

Character string or numeric vector specifying legend position. Default: "bottom".

color_palette

Function or character vector for color palette. If NULL, uses ggplot2 default colors. Default: NULL.

add_grid_lines

Logical indicating whether to add dashed grid lines at origin. Default: TRUE.

color_points

Character string specifying which classification to use for point colors. Either "primary" (uses class_column) or "alternative" (uses alternative_class_column). Default: "primary".

fill_voronoi

Character string specifying which classification to use for Voronoi fill. Either "primary" (uses class_column) or "alternative" (uses alternative_class_column). Default: "primary".

point_shape

Character string specifying which classification to use for point shapes. Either "primary" (uses class_column), "alternative" (uses alternative_class_column), or "none" (no shape differentiation). Default: "none".

label_fontface

Character string specifying the font face for text labels. Options include "plain", "bold", "italic", "bold.italic". Default: "plain".

label_size

Numeric value specifying the size of text labels. Default: 3.88.

Details

The function creates a Voronoi tessellation visualization for 2D projected data, particularly useful for displaying results from dimensionality reduction techniques. Voronoi tessellation divides the plot space into regions based on proximity to data points, providing an intuitive visualization of class boundaries and decision regions.

Value

A ggplot object showing the Voronoi tessellation plot.

Examples

# Basic usage with iris dataset
data <- iris[, c("Sepal.Length", "Petal.Length", "Species")]
plot <- create_voronoi_plot(
  data = data,
  class_column = "Species",
  legend_position = "bottom",
  add_grid_lines = FALSE
)