R: Run a plotting function and save the output as a PNG

plotPNG {shiny} | R Documentation

## Run a plotting function and save the output as a PNG

### Description

This function returns the name of the PNG file that it generates. In essence, it calls `png()`, then `func()`, then `dev.off()`. So `func` must be a function that will generate a plot when used this way.

### Usage

    plotPNG(func, filename = tempfile(fileext = ".png"), width = 400,
      height = 400, res = 72, ...)

### 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 `png`. 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 `png`. These can be used to set the width, height, background color, etc.

### Details

For output, it will try to use the following devices, in this order: quartz (via `png`), then `CairoPNG`, and finally `png`. This is in order of quality of output. Notably, plain `png` output on Linux and Windows may not antialias some point shapes, resulting in poor quality output.

In some cases, `Cairo()` provides output that looks worse than `png()`. To disable Cairo output for an app, use `options(shiny.usecairo=FALSE)`.

[Package shiny version 1.0.5 Index]