Capture a plot as a PNG file. — plotPNG
R/imageutils.R
  Description
The PNG graphics device used is determined in the following order:
- If the ragg package is installed (and the - shiny.useraggis not set to- FALSE), then use- ragg::agg_png().
- If a quartz device is available (i.e., - capabilities("aqua")is- TRUE), then use- png(type = "quartz").
- If the Cairo package is installed (and the - shiny.usecairooption is not set to- FALSE), then use- Cairo::CairoPNG().
- Otherwise, use - grDevices::png(). In this case, Linux and Windows may not antialias some point shapes, resulting in poor quality output.
Arguments
- func
- A function that generates a plot. 
- filename
- The name of the output file. Defaults to a temp file with extension - .png.
- width
- Width in pixels. 
- height
- Height in pixels. 
- res
- Resolution in pixels per inch. This value is passed to the graphics device. 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 the graphics device. These can be used to set the width, height, background color, etc. 
Value
A path to the newly generated PNG file.
Details
A NULL value provided to width or height is ignored (i.e., the
default width or height of the graphics device is used).