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45 lines
1.6 KiB
R
45 lines
1.6 KiB
R
% Generated by roxygen2: do not edit by hand
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% Please edit documentation in R/imageutils.R
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\name{plotPNG}
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\alias{plotPNG}
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\title{Run a plotting function and save the output as a PNG}
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\usage{
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plotPNG(func, filename = tempfile(fileext = ".png"), width = 400,
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height = 400, res = 72, ...)
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}
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\arguments{
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\item{func}{A function that generates a plot.}
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\item{filename}{The name of the output file. Defaults to a temp file with
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extension \code{.png}.}
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\item{width}{Width in pixels.}
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\item{height}{Height in pixels.}
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\item{res}{Resolution in pixels per inch. This value is passed to
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\code{\link[grDevices]{png}}. Note that this affects the resolution of PNG rendering in
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R; it won't change the actual ppi of the browser.}
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\item{...}{Arguments to be passed through to \code{\link[grDevices]{png}}.
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These can be used to set the width, height, background color, etc.}
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}
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\description{
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This function returns the name of the PNG file that it generates. In
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essence, it calls \code{png()}, then \code{func()}, then \code{dev.off()}.
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So \code{func} must be a function that will generate a plot when used this
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way.
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}
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\details{
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For output, it will try to use the following devices, in this order:
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quartz (via \code{\link[grDevices]{png}}), then \code{\link[Cairo]{CairoPNG}},
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and finally \code{\link[grDevices]{png}}. This is in order of quality of
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output. Notably, plain \code{png} output on Linux and Windows may not
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antialias some point shapes, resulting in poor quality output.
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In some cases, \code{Cairo()} provides output that looks worse than
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\code{png()}. To disable Cairo output for an app, use
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\code{options(shiny.usecairo=FALSE)}.
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}
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