shinyMat

A lightweight editable matrix input for Shiny.

shinyMat renders a small grid of text inputs that reports its value to Shiny as a matrix. The client binding is a single dependency-free vanilla-JavaScript file — no Vue, no lodash, no build step — attached automatically as an htmlDependency, so apps need no addResourcePath() setup. It is a trimmed reimplementation of the subset of shinyMatrix that typical apps use: a static header row of column names plus editable cells, with the matrix resized from the server rather than the client.

Installation

# install from r-universe
install.packages("shinyMat", repos = "https://yihui.r-universe.dev")

# or the development version from GitHub
remotes::install_github("yihui/shinyMat")

Usage

library(shiny)
library(shinyMat)

ui = fluidPage(
  matrixInput(
    "m", "Edit the cells:",
    value = matrix(c(12, 24, 0.8, 0.6), 2, dimnames = list(NULL, c("Time", "Rate"))),
    class = "numeric"
  ),
  verbatimTextOutput("out")
)

server = function(input, output, session) {
  output$out = renderPrint(input$m)

  # Replace the whole matrix from the server (e.g. add/remove rows, reset):
  # updateMatrixInput(session, "m", new_matrix)
}

shinyApp(ui, server)

Functions

• matrixInput() — create the input. value is a [matrix]; its row/column names become the headers. class is "character" or "numeric" (numeric inputs reject non-numeric cells on the client).
• updateMatrixInput() — replace the full matrix from the server; the client re-renders and reports the new value back to Shiny.

The value read from input[[inputId]] is a matrix of the chosen storage mode, with the row/column names supplied to matrixInput()/updateMatrixInput().

Acknowledgements

This package was written with the help of Claude Code. It is a Vue-free, trimmed reimplementation of shinyMatrix by INWT Statistics; the original is more full-featured (pagination, editable and multi-level headers, client-side row/column extension, copy/paste).