shiny/man/plotPNG.Rd

\name{plotPNG}
\alias{plotPNG}
\title{Run a plotting function and save the output as a PNG}
\usage{
  plotPNG(func, filename = tempfile(fileext = ".png"),
    width = 400, height = 400, res = 72, ...)
}
\arguments{
  \item{func}{A function that generates a plot.}

  \item{filename}{The name of the output file. Defaults to
  a temp file with extension \code{.png}.}

  \item{width}{Width in pixels.}

  \item{height}{Height in pixels.}

  \item{res}{Resolution in pixels per inch. This value is
  passed to \code{\link{png}}. Note that this affects the
  resolution of PNG rendering in R; it won't change the
  actual ppi of the browser.}

  \item{...}{Arguments to be passed through to
  \code{\link[grDevices]{png}}.  These can be used to set
  the width, height, background color, etc.}
}
\description{
  This function returns the name of the PNG file that it
  generates. In essence, it calls \code{png()}, then
  \code{func()}, then \code{dev.off()}. So \code{func} must
  be a function that will generate a plot when used this
  way.
}
\details{
  For output, it will try to use the following devices, in
  this order: quartz (via \code{\link[grDevices]{png}}),
  then \code{\link[Cairo]{CairoPNG}}, and finally
  \code{\link[grDevices]{png}}. This is in order of quality
  of output. Notably, plain \code{png} output on Linux and
  Windows may not antialias some point shapes, resulting in
  poor quality output.
}