Renders a reactive plot that is suitable for assigning to an output
slot.
renderPlot(
expr,
width = "auto",
height = "auto",
res = 72,
...,
alt = NA,
env = parent.frame(),
quoted = FALSE,
execOnResize = FALSE,
outputArgs = list()
)
An expression that generates a plot.
Height and width can be specified in three ways:
"auto"
, the default, uses the size specified by plotOutput()
(i.e. the offsetWidth
/`offsetHeight`` of the HTML element bound to
this plot.)
An integer, defining the width/height in pixels.
A function that returns the width/height in pixels (or "auto"
).
The function is executed in a reactive context so that you can refer to
reactive values and expression to make the width/height reactive.
When rendering an inline plot, you must provide numeric values (in pixels)
to both width
and height
.
Resolution of resulting plot, in pixels per inch. This value is
passed to plotPNG()
. Note that this affects the resolution of PNG
rendering in R; it won't change the actual ppi of the browser.
Arguments to be passed through to plotPNG()
.
These can be used to set the width, height, background color, etc.
Alternate text for the HTML <img>
tag if it cannot be displayed
or viewed (i.e., the user uses a screen reader). In addition to a character
string, the value may be a reactive expression (or a function referencing
reactive values) that returns a character string. If the value is NA
(the
default), then ggplot2::get_alt_text()
is used to extract alt text from
ggplot objects; for other plots, NA
results in alt text of "Plot object".
NULL
or ""
is not recommended because those should be limited to
decorative images.
The parent environment for the reactive expression. By default,
this is the calling environment, the same as when defining an ordinary
non-reactive expression. If expr
is a quosure and quoted
is TRUE
,
then env
is ignored.
If it is TRUE
, then the quote()
ed value of expr
will be used when expr
is evaluated. If expr
is a quosure and you
would like to use its expression as a value for expr
, then you must set
quoted
to TRUE
.
If FALSE
(the default), then when a plot is
resized, Shiny will replay the plot drawing commands with
grDevices::replayPlot()
instead of re-executing expr
.
This can result in faster plot redrawing, but there may be rare cases where
it is undesirable. If you encounter problems when resizing a plot, you can
have Shiny re-execute the code on resize by setting this to TRUE
.
A list of arguments to be passed through to the implicit
call to plotOutput()
when renderPlot
is used in an
interactive R Markdown document.
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 plotOutput()
for more information about interactive plots.
The corresponding HTML output tag should be div
or img
and have
the CSS class name shiny-plot-output
.
For the corresponding client-side output function, and example
usage, see plotOutput()
. For more details on how the plots are
generated, and how to control the output, see plotPNG()
.
renderCachedPlot()
offers a way to cache generated plots to
expedite the rendering of identical plots.