Animated Biplots

Create animated biplots that enables dynamic visualisation of temporal or sequential changes in multivariate data by animating a single biplot across the levels of a time variable. It builds on objects from the 'biplotEZ' package, Lubbe S, le Roux N, Nienkemper-Swanepoel J, Ganey R, Buys R, Adams Z, Manefeldt P (2024) , allowing users to create animated biplots that reveal how both samples and variables evolve over time.

moveEZ

moveEZ (pronounced move easy) extends the biplotEZ package to animate PCA biplots across the ordered levels of a categorical variable. Rather than producing a separate static biplot per level, which fragments sequential information and makes gradual structural change difficult to perceive, moveEZ renders transitions between levels as a continuous animation.

Installation

Install the released version from CRAN:

install.packages("moveEZ")

Or install the development version from GitHub:

# install.packages("devtools")
devtools::install_github("MuViSU/moveEZ")

Overview

moveEZ animates PCA biplots across the ordered levels of a categorical variable — referred to as the time variable. This variable need not represent chronological time; it may be any ordered index such as experimental stages, algorithmic iterations, or measurement occasions. Each distinct level of the time variable defines a time slice: the subset of observations corresponding to that level.

The package provides three animation functions of increasing methodological complexity:

All three functions support animated output (move = TRUE) and static faceted output (move = FALSE).

Basic usage

library(moveEZ)
library(biplotEZ)

data("Africa_climate")

bp <- biplot(Africa_climate, scaled = TRUE) |>
  PCA(group.aes = Africa_climate$Region) |>
  samples(opacity = 0.8) |>
  plot()

# Static faceted display
bp |> moveplot(time.var = "Year", group.var = "Region",
               hulls = TRUE, move = FALSE)

# Animated display
bp |> moveplot(time.var = "Year", group.var = "Region",
               hulls = TRUE, move = TRUE)

Learn more

• Vignette: a full applied demonstration of all three functions, including animated outputs, evaluation measures, and aesthetic customisation - vignette("moveEZ"). Also consult the package website.
• Paper: the preprint provides the complete methodology, including the theoretical motivation for each framework.

Report bugs and get support

If you encounter any issues or have questions, please open an issue on the GitHub repository.

About the logo

Logo concept developed with assistance from OpenAI's ChatGPT (https://openai.com/chatgpt); final design by Raeesa and Johané.