shinymodist

A lightweight Shiny input wrapper around modist: draggable probability distributions that behave like regular Shiny inputs.

shinymodist keeps the default presentation compact and low-noise, while retaining an opt-in style = "modist" mode close to the upstream experience.

Install

pak::pak("jbkunst/shinymodist")

Basic use

library(shiny)
library(shinymodist)

ui <- bslib::page_sidebar(
  title = "Basic shinymodist input",
  sidebar = bslib::sidebar(
    modist_input(
      "dist",
      family = "normal",
      value = list(mu = 0, sigma = 1)
    )
  ),
  bslib::card(
    bslib::card_header("Reactive value"),
    verbatimTextOutput("value")
  )
)

server <- function(input, output, session) {
  output$value <- renderPrint(input$dist)
}

shinyApp(ui, server)

The input returns the distribution family and its canonical parameters:

list(
  family = "normal",
  mu = 0,
  sigma = 1
)

A fixed visible scale can be supplied when comparisons need a common domain:

modist_input(
  "scores",
  family = "normal",
  value = list(mu = 1, sigma = 1),
  domain = c(-5, 5)
)

Server-side updates use update_modist_input().

Styles and bslib

The default style = "minimal" is intentionally quiet: no grid or toolbar, and its visual accents inherit --bs-primary when used inside a bslib theme.

bslib::page_fluid(
  theme = bslib::bs_theme(primary = "#6f42c1"),
  modist_input("dist")
)

Use style = "modist" to keep the original modist appearance and controls.

The input is responsive by default. A fixed CSS height is available only when the surrounding layout needs it:

modist_input("dist", height = "180px")

The default height = NULL keeps the current aspect-ratio behavior.

Live demos

The pkgdown site exports the package examples with Shinylive, so they run entirely in the browser with webR:

• Basic input
• Distribution gallery
• ROC curve
• Beta-Binomial

A rolling dev GitHub prerelease carries the WebAssembly library image for the current main branch. This lets the site exercise the latest package without requiring a local clone.

Distribution families

The wrapper exposes all distribution families bundled by modist:

• Normal, Beta, Gamma and Student t
• Exponential, Half Normal and Log Normal
• Cauchy, Laplace and Logistic
• Weibull, Half Student t and Chi-squared
• Inverse Gamma and Kumaraswamy

All families use the same modist_input() API. See the distribution gallery for a compact grid plus narrow-sidebar examples.

WebAssembly and Shinylive

WebAssembly compatibility is treated as a supported deployment target. Every push is checked with the r-wasm toolchain. Package releases also build a webR filesystem image so the package can be bundled by Shinylive without compiling R packages in the browser.

The pkgdown workflow exports the runnable examples with Shinylive using the rolling WebAssembly dev release. Stable GitHub releases keep their own immutable WebAssembly library images.

Documentation: https://jkunst.com/shinymodist/

Credits

shinymodist wraps the JavaScript distribution widgets from William Dean’s modist, distributed under the MIT License.

The compact Shiny-input philosophy is also inspired by Carson Sievert’s histoslider.

License

MIT