Create an plot or image output element — plotOutput
R/bootstrap.R
Description
Render a renderPlot()
or renderImage()
within an
application page.
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 wheninline = TRUE
, in which case the width/height of a plot must be specified inrenderPlot()
. 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 theclickOpts()
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 viainput$plot_click
. The value will be a named list withx
andy
elements indicating the mouse position.- dblclick
This is just like the
click
argument, but for double-click events.- hover
Similar to the
click
argument, this can beNULL
(the default), a string, or an object created by thehoverOpts()
function. If you use a value like"plot_hover"
(or equivalently,hoverOpts(id="plot_hover")
), the plot will send coordinates to the server pauses on the plot, and the value will be accessible viainput$plot_hover
. The value will be a named list withx
andy
elements indicating the mouse position. To control the hover time or hover delay type, you must usehoverOpts()
.- brush
Similar to the
click
argument, this can beNULL
(the default), a string, or an object created by thebrushOpts()
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 viainput$plot_brush
. Brushing means that the user will be able to draw a rectangle in the plotting area and drag it around. The value will be a named list withxmin
,xmax
,ymin
, andymax
elements indicating the brush area. To control the brush behavior, usebrushOpts()
. MultipleimageOutput
/plotOutput
calls may share the sameid
value; brushing one image or plot will cause any other brushes with the sameid
to disappear.- inline
use an inline (
span()
) or block container (div()
) for the output
Value
A plot or image output element that can be included in a panel.
Note
The arguments clickId
and hoverId
only work for R base graphics
(see the graphics package). They do
not work for grid-based graphics, such as
ggplot2, lattice, and so on.
Interactive plots
Plots and images in Shiny support mouse-based interaction, via clicking,
double-clicking, hovering, and brushing. When these interaction events
occur, the mouse coordinates will be sent to the server as input$
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.
See also
For the corresponding server-side functions, see renderPlot()
and
renderImage()
.
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)
})
}
)
}