maidr

Overview

maidr (Multimodal Access and Interactive Data Representation) makes data visualizations accessible to users with visual impairments. It converts ggplot2 and Base R plots into interactive, accessible HTML/SVG formats with keyboard navigation, screen reader support, and sonification.

The package provides two main functions:

• show() displays an interactive accessible plot in RStudio Viewer or browser
• save_html() exports a plot as a standalone HTML file

Installation

Install the stable release from CRAN:

install.packages("maidr")

Or install the development version from GitHub:

# Using pak (recommended)
pak::pak("xability/r-maidr")

# Alternative: using pacman (auto-installs if missing)
pacman::p_load_gh("xability/r-maidr")

Usage

ggplot2

library(maidr)
library(ggplot2)

p <- ggplot(mpg, aes(x = class)) +
  geom_bar(fill = "steelblue") +
  labs(title = "Vehicle Classes", x = "Class", y = "Count")

# Display interactive accessible plot
show(p)

# Or save to file
save_html(p, "vehicle_classes.html")

Base R

library(maidr)

# Create plot first
barplot(
  table(mtcars$cyl),
  main = "Cars by Cylinder Count",
  xlab = "Cylinders",
  ylab = "Count"
)

# Then call show() without arguments
show()

Supported plot types

maidr supports a wide range of visualization types in both ggplot2 and Base R:

Basic Plot Types

Plot Type	ggplot2	Base R
Bar charts	geom_bar(), geom_col()	barplot()
Grouped/Dodged bars	position = "dodge"	beside = TRUE
Stacked bars	position = "stack"	beside = FALSE
Histograms	geom_histogram()	hist()
Scatter plots	geom_point()	plot()
Line plots	geom_line()	plot(type = "l"), lines()
Box plots	geom_boxplot()	boxplot()
Heatmaps	geom_tile()	image()
Violin plots	geom_violin()	—
Candlestick (OHLC)	tidyquant::geom_candlestick() (+ geom_ma(), + patchwork volume)	quantmod::chartSeries() (OHLC-only; no TA / no volume)
Density/Smooth	geom_smooth(), geom_density()	lines(density())

Note: Volume bars and moving-average overlays for candlestick charts are supported only on the ggplot2 + {tidyquant} + {patchwork} path. On the Base R path, quantmod::chartSeries() TA overlays (addVo(), addSMA(), addEMA()) — and the default TA whenever the input xts carries a Volume column — fall back to native (non-accessible) graphics with a one-time advisory.

Advanced Plot Types

Plot Type	ggplot2	Base R
Faceted plots	facet_wrap(), facet_grid()	par(mfrow/mfcol) + loops
Multi-panel layouts	patchwork package	par(mfrow), par(mfcol)
Multi-layered plots	Multiple geom_* layers	Sequential plot calls

See vignette("plot-types") for detailed examples of each plot type.

Accessibility features

• Keyboard navigation - explore data points using arrow keys
• Screen reader support - full ARIA labels and live announcements
• Sonification - hear data patterns through sound
• Text descriptions - automatic statistical summaries

Offline support

By default, maidr auto-detects internet availability and loads the MAIDR.js library from a CDN. Use the use_cdn parameter for explicit control:

# Force CDN (requires internet)
show(p, use_cdn = TRUE)

# Force bundled files (works offline)
show(p, use_cdn = FALSE)
save_html(p, "plot.html", use_cdn = FALSE)

Getting help

• Report bugs or request features at GitHub Issues
• Read the documentation at the package website

Learning more

• vignette("getting-started", package = "maidr") for an introduction
• vignette("plot-types", package = "maidr") for supported visualizations
• vignette("shiny-integration", package = "maidr") for Shiny apps