agg_ppm {ragg}

Draw to a PPM file

Description

The PPM (Portable Pixel Map) format defines one of the simplest storage formats available for image data. It is basically a raw 8bit RGB stream with a few bytes of information in the start. It goes without saying, that this file format is horribly inefficient and should only be used if you want to play around with a simple file format, or need a file-based image stream.

Usage

agg_ppm(
  filename = "Rplot%03d.ppm",
  width = 480,
  height = 480,
  units = "px",
  pointsize = 12,
  background = "white",
  res = 72,
  scaling = 1,
  snap_rect = TRUE,
  bg
)

Arguments

filename

The name of the file. Follows the same semantics as the file naming in grDevices::png(), meaning that you can provide a sprintf() compliant string format to name multiple plots (such as the default value)

width, height

The dimensions of the device

units

The unit width and height is measured in, in either pixels ('px'), inches ('in'), millimeters ('mm'), or centimeter ('cm').

pointsize

The default pointsize of the device in pt. This will in general not have any effect on grid graphics (including ggplot2) as text size is always set explicitly there.

background

The background colour of the device

res

The resolution of the device. This setting will govern how device dimensions given in inches, centimeters, or millimeters will be converted to pixels. Further, it will be used to scale text sizes and linewidths

scaling

A scaling factor to apply to the rendered line width and text size. Useful for getting the right dimensions at the resolution that you need. If e.g. you need to render a plot at 4000x3000 pixels for it to fit into a layout, but you find that the result appears to small, you can increase the scaling argument to make everything appear bigger at the same resolution.

snap_rect

Should axis-aligned rectangles drawn with only fill snap to the pixel grid. This will prevent anti-aliasing artifacts when two rectangles are touching at their border.

bg

Same as background for compatibility with old graphic device APIs

Examples

file <- tempfile(fileext = '.ppm')
agg_ppm(file)
plot(sin, -pi, 2*pi)
dev.off()