Shiny by RStudio

Create an plot or image output element

imageOutput(outputId, width = "100%", height = "400px", click = NULL,
  dblclick = NULL, hover = NULL, hoverDelay = NULL,
  hoverDelayType = NULL, brush = NULL, clickId = NULL, hoverId = NULL,
  inline = FALSE)

plotOutput(outputId, width = "100%", height = "400px", click = NULL,
  dblclick = NULL, hover = NULL, hoverDelay = NULL,
  hoverDelayType = NULL, brush = NULL, clickId = NULL, hoverId = NULL,
  inline = FALSE)

Arguments

outputId output variable to read the plot/image from.
width, height Image width/height. Must be a valid CSS unit (like "100%", "400px", "auto") or a number, which will be coerced to a string and have "px" appended. These two arguments are ignored when inline = TRUE, in which case the width/height of a plot must be specified in renderPlot(). Note that, for height, using "auto" or "100%" generally will not work as expected, because of how height is computed with HTML/CSS.
click This can be NULL (the default), a string, or an object created by the clickOpts function. If you use a value like "plot_click" (or equivalently, clickOpts(id="plot_click")), the plot will send coordinates to the server whenever it is clicked, and the value will be accessible via input$plot_click. The value will be a named list with x and y elements indicating the mouse position.
dblclick This is just like the click argument, but for double-click events.
hover Similar to the click argument, this can be NULL (the default), a string, or an object created by the hoverOpts function. If you use a value like "plot_hover" (or equivalently, hoverOpts(id="plot_hover")), the plot will send coordinates to the server pauses on the plot, and the value will be accessible via input$plot_hover. The value will be a named list with x and y elements indicating the mouse position. To control the hover time or hover delay type, you must use hoverOpts.
hoverDelay Deprecated; use hover instead. Also see the hoverOpts function.
hoverDelayType Deprecated; use hover instead. Also see the hoverOpts function.
brush Similar to the click argument, this can be NULL (the default), a string, or an object created by the brushOpts function. If you use a value like "plot_brush" (or equivalently, brushOpts(id="plot_brush")), the plot will allow the user to "brush" in the plotting area, and will send information about the brushed area to the server, and the value will be accessible via input$plot_brush. Brushing means that the user will be able to draw a rectangle in the plotting area and drag it around. The value will be a named list with xmin, xmax, ymin, and ymax elements indicating the brush area. To control the brush behavior, use brushOpts. Multiple imageOutput/plotOutput calls may share the same id value; brushing one image or plot will cause any other brushes with the same id to disappear.
clickId Deprecated; use click instead. Also see the clickOpts function.
hoverId Deprecated; use hover instead. Also see the hoverOpts function.
inline use an inline (span()) or block container (div()) for the output

Value

A plot or image output element that can be included in a panel.

Description

Render a renderPlot or renderImage within an application page.

Note

The arguments clickId and hoverId only work for R base graphics (see the graphics package). They do not work for grid-based graphics, such as ggplot2, lattice, and so on.

Interactive plots

Plots and images in Shiny support mouse-based interaction, via clicking, double-clicking, hovering, and brushing. When these interaction events occur, the mouse coordinates will be sent to the server as input$ variables, as specified by click, dblclick, hover, or brush.

For plotOutput, the coordinates will be sent scaled to the data space, if possible. (At the moment, plots generated by base graphics and ggplot2 support this scaling, although plots generated by lattice and others do not.) If scaling is not possible, the raw pixel coordinates will be sent. For imageOutput, the coordinates will be sent in raw pixel coordinates.

With ggplot2 graphics, the code in renderPlot should return a ggplot object; if instead the code prints the ggplot2 object with something like print(p), then the coordinates for interactive graphics will not be properly scaled to the data space.

Examples

# Only run these examples in interactive R sessions if (interactive()) { # A basic shiny app with a plotOutput shinyApp( ui = fluidPage( sidebarLayout( sidebarPanel( actionButton("newplot", "New plot") ), mainPanel( plotOutput("plot") ) ) ), server = function(input, output) { output$plot <- renderPlot({ input$newplot # Add a little noise to the cars data cars2 <- cars + rnorm(nrow(cars)) plot(cars2) }) } ) # A demonstration of clicking, hovering, and brushing shinyApp( ui = basicPage( fluidRow( column(width = 4, plotOutput("plot", height=300, click = "plot_click", # Equiv, to click=clickOpts(id="plot_click") hover = hoverOpts(id = "plot_hover", delayType = "throttle"), brush = brushOpts(id = "plot_brush") ), h4("Clicked points"), tableOutput("plot_clickedpoints"), h4("Brushed points"), tableOutput("plot_brushedpoints") ), column(width = 4, verbatimTextOutput("plot_clickinfo"), verbatimTextOutput("plot_hoverinfo") ), column(width = 4, wellPanel(actionButton("newplot", "New plot")), verbatimTextOutput("plot_brushinfo") ) ) ), server = function(input, output, session) { data <- reactive({ input$newplot # Add a little noise to the cars data so the points move cars + rnorm(nrow(cars)) }) output$plot <- renderPlot({ d <- data() plot(d$speed, d$dist) }) output$plot_clickinfo <- renderPrint({ cat("Click:\n") str(input$plot_click) }) output$plot_hoverinfo <- renderPrint({ cat("Hover (throttled):\n") str(input$plot_hover) }) output$plot_brushinfo <- renderPrint({ cat("Brush (debounced):\n") str(input$plot_brush) }) output$plot_clickedpoints <- renderTable({ # For base graphics, we need to specify columns, though for ggplot2, # it's usually not necessary. res <- nearPoints(data(), input$plot_click, "speed", "dist") if (nrow(res) == 0) return() res }) output$plot_brushedpoints <- renderTable({ res <- brushedPoints(data(), input$plot_brush, "speed", "dist") if (nrow(res) == 0) return() res }) } ) # Demo of clicking, hovering, brushing with imageOutput # Note that coordinates are in pixels shinyApp( ui = basicPage( fluidRow( column(width = 4, imageOutput("image", height=300, click = "image_click", hover = hoverOpts( id = "image_hover", delay = 500, delayType = "throttle" ), brush = brushOpts(id = "image_brush") ) ), column(width = 4, verbatimTextOutput("image_clickinfo"), verbatimTextOutput("image_hoverinfo") ), column(width = 4, wellPanel(actionButton("newimage", "New image")), verbatimTextOutput("image_brushinfo") ) ) ), server = function(input, output, session) { output$image <- renderImage({ input$newimage # Get width and height of image output width <- session$clientData$output_image_width height <- session$clientData$output_image_height # Write to a temporary PNG file outfile <- tempfile(fileext = ".png") png(outfile, width=width, height=height) plot(rnorm(200), rnorm(200)) dev.off() # Return a list containing information about the image list( src = outfile, contentType = "image/png", width = width, height = height, alt = "This is alternate text" ) }) output$image_clickinfo <- renderPrint({ cat("Click:\n") str(input$image_click) }) output$image_hoverinfo <- renderPrint({ cat("Hover (throttled):\n") str(input$image_hover) }) output$image_brushinfo <- renderPrint({ cat("Brush (debounced):\n") str(input$image_brush) }) } ) }

See also

For the corresponding server-side functions, see renderPlot and renderImage.