ggInterval

ggInterval (formerly ggESDA) is an R package for visualizing interval-valued symbolic data using ggplot2.

Overview

Exploratory data analysis (EDA) relies on graphical summaries such as boxplots, histograms, and scatterplots. Yet modern data are increasingly structurally rich: single observations may be recorded not as scalars but as intervals, histograms, or full empirical distributions — collectively known as symbolic data. Conventional graphics cannot natively accommodate these objects.

ggInterval bridges this gap by extending ggplot2 to support interval-valued data. It provides seamless integration with the ggplot2 workflow, enabling analysts to uncover structure and anomalies in interval-valued data that would remain hidden with traditional scalar-oriented graphics.

Installation

Install the released version from CRAN:

install.packages("ggInterval")

Or install the development version from GitHub:

# install.packages("devtools")
devtools::install_github("hanmingwu1103/ggInterval")

Features

Visualization Functions

Function	Description
ggInterval_scatterplot	Scatter plot for two continuous interval variables
ggInterval_scatterMatrix	Scatter plot matrix for all continuous interval variables
ggInterval_3Dscatterplot	3D scatter plot for three interval variables
ggInterval_MMplot	Min-max plot showing the range of each observation
ggInterval_CRplot	Center-range plot showing the relation between center and range
ggInterval_indexplot	Index plot displaying the range of each observation with margin bars
ggInterval_indexImage	Index image plot
ggInterval_hist	Histogram for interval data
ggInterval_2Dhist	2D histogram for interval data
ggInterval_2DhistMatrix	2D histogram matrix for interval data
ggInterval_boxplot	Boxplot for interval data
ggInterval_radarplot	Radar plot with multiple interval variables
ggInterval_PCA	PCA biplot for interval data

Data Transformation

Function	Description
classic2sym	Convert classical data to symbolic interval data via clustering or custom methods
RSDA2sym	Convert RSDA symbolic objects to ggInterval format

Quick Start

library(ggInterval)

# Convert classical data to symbolic interval data
myIris <- classic2sym(iris, groupby = "Species")$intervalData

Scatter Plot

ggInterval_scatterplot(myIris, aes(x = Petal.Length, y = Petal.Width))

Min-Max Plot

ggInterval_MMplot(myIris, aes(Sepal.Length))

Center-Range Plot

ggInterval_CRplot(myIris, aes(Sepal.Length))

Index Plot

ggInterval_indexplot(myIris, aes(x = Sepal.Width))

Index Image

ggInterval_indexImage(myIris, aes(x = Sepal.Length))

Boxplot

ggInterval_boxplot(myIris, aes(x = Sepal.Length))

Histogram

ggInterval_hist(myIris, aes(x = Petal.Length))

Radar Plot

ggInterval_radarplot(myIris, plotPartial = 1:3, showLegend = TRUE)

Links

• CRAN: https://CRAN.R-project.org/package=ggInterval
• Vignette: ggInterval_intro.html

Citation

Jiang, B.S. and Wu, H.M. (2025), ggInterval: an R package for visualizing interval-valued data using ggplot2. R package version 0.2.3, https://CRAN.R-project.org/package=ggInterval.

License

GPL (>= 2)