JPlotToPNG: Plot to a PNG file

In JimMcL/JUtils: Some R Utilities

Plot to a PNG file

Description

Writes the output of a plot to a PNG file. If you are using ggplot, try either using JPlotToPNG(filename, print(<plotting code>)) or else ggsave().

Usage

JPlotToPNG(
  filename,
  plotExpr,
  width = 600,
  height = NA,
  aspectRatio = 3/2,
  units = c("px", "mm", "cm", "in"),
  tryToUseRagg = TRUE,
  type = ifelse(capabilities()["cairo"], "cairo", NULL),
  res = 72,
  onlyIfDoesntExist = FALSE,
  createDirectory = TRUE,
  ...
)

Arguments

filename	The name of the PNG to create or overwrite. If NULL, plot output goes to the current device.
plotExpr	A function or expression which will produce the plot to be written to the file.
width	The width of the output PNG file in units.
height	The height of the output PNG file in units. Defaults to width / aspectRatio. If height is specified, aspectRatio will be ignored.
aspectRatio	Aspect ratio (width / height) of the output PNG file.
units	Units of width and height. Note that defaults units are pixels (px).
tryToUseRagg	If TRUE (the default) and the ragg package is installed, the PNG file will be created using agg_png, otherwise png will be used. See https://ragg.r-lib.org for more information.
type	Plotting device; passed directly to png. Defaults to "cairo" if that is an available device since it produces nicer looking graphics. Ignored if tryToUseRagg == TRUE and ragg is installed. Note that R can be compiled with Cairo support, but it still won't work on MacOS if Quartz is not installed.
res	The nominal resolution in ppi. The value is simply passed in to agg_png or png. Increasing the resolution will increase the size (in pixels) of the text and graph elements.
onlyIfDoesntExist	If TRUE and the output file already exists, JPlotToPNG will do nothing.
createDirectory	If TRUE and filename is located in a directory which doesn't exist, the directory will be created.
...	Any additional arguments are passed to either agg_png or png.

Value

The result of evaluating plotExpr is returned invisibly (which means it is not automatically printed).

See Also

agg_png, png

Examples

## Not run: 
JPlotToPNG("test.png", plot(rnorm(50), type = 'l', main = 'Wiggly line'))

# Plot to a PNG file with width 180 mm, height 120 mm
# (i.e. height / aspectRatio which defaults to (3 / 2)), resolution 300 ppi.
# This results in a PNG file with size 2125x1417 pixels
JPlotToPNG("test.png", plot(1:10 + rnorm(10), type = "o"), width = 180, units = "mm", res = 300)

## End(Not run)

JimMcL/JUtils documentation built on Nov. 7, 2024, 11:25 a.m.