library(ggplot2) library(shiny)

Call ggbrush with a ggplot2 object, and the dimensions which

should be brushed (try "xy" for scatter, "x" for histogram).

The plot will show in RStudio Viewer or your web browser, and

any observations selected by the user will be returned.

ggbrush <- function(plotExpr, direction = c("xy", "x", "y")) {

See below for definition of dialogPage function

ui <- dialogPage( plotOutput("plot", brush = brushOpts(id = "brush", direction = direction), width = "100%", height = "100%" # Fill the dialog ) )

server <- function(input, output, session) { # Show the plot... that's important. output$plot <- renderPlot(plotExpr)

# The part of the data frame that is currently brushed (or
# NULL if no brush is active)
brushed <- reactive({
  if (is.null(input$brush))
    return(NULL)
  else
    brushedPoints(plotExpr$data, input$brush)
})

# Show a message giving instructions, or showing how many
# rows are selected
output$msg <- renderText({
  if (is.null(brushed()))
    return("Click and drag to select, then press Done \u27f6")
  
  count <- nrow(brushed())
  sprintf("%d %s selected",
    count, 
    ifelse(count == 1, "observation", "observations")
  )
})

# When the Done button is clicked, return the brushed
# rows to the caller.
observeEvent(input$done, {
  stopApp(brushed())
})

}

shiny::runApp(shinyApp(ui, server), launch.browser = getOption("viewer", TRUE)) }

Helper function to present Shiny controls in a dialog-like layout

dialogPage <- function(outputControl) { bootstrapPage( tagsstyle(" html, body { width: 100%; height: 100%; overflow: none; } #dialogMainOutput { position: absolute; top: 10px; left: 10px; right: 10px; bottom: 40px; } #dialogControls { position: absolute; bottom: 0px; left: 0px; right: 0px; height: 40px; padding: 10px 10px 0 10px; background-color: #444; color: white; }"), tagsdiv(id = "dialogMainOutput", outputControl), tags$div(id = "dialogControls", textOutput("msg", inline = TRUE), actionButton("done", "Done", class = "btn btn-primary btn-xs pull-right") ) ) }

#' @examples #' #' p <- ggplot(diamonds, aes(carat, price)) + geom_point() + facet_wrap(~cut) #' ggbrush(p) #' #' p <- ggplot(diamonds, aes(x=carat)) + geom_bar() #' ggbrush(p, direction = "x")