JPlotToJPEG: Plot to a JPEG file

In JimMcL/JUtils: Some R Utilities

Plot to a JPEG file

Description

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

Usage

JPlotToJPEG(
  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 JPEG 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 JPEG file in units.
height	The height of the output JPEG file in units. Defaults to width / aspectRatio. If height is specified, aspectRatio will be ignored.
aspectRatio	Aspect ratio (width / height) of the output JPEG 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 JPEG file will be created using agg_jpeg, otherwise jpeg will be used. See https://ragg.r-lib.org for more information.
type	Plotting device; passed directly to jpeg. Defaults to "cairo" if that is an available device since it produces nicer looking graphics. Ignored if tryToUseRagg == TRUE and ragg is installed.
res	The nominal resolution in ppi. The value is passed unchanged in to agg_jpeg or jpeg. Increasing the resolution will increase the size (in pixels) of the text and graph elements.
onlyIfDoesntExist	If TRUE and the output file already exists, JPlotToJPEG 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 agg_jpeg or jpeg.

Value

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

See Also

agg_jpeg, jpeg

Examples

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

# Plot to a JPEG file with width 180 mm, height 120 mm
# (i.e. height / aspectRatio which defaults to (3 / 2)), resolution 300 ppi.
# This results in a JPEG file with size 2125x1417 pixels
JPlotToJPEG("test.jpg", 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.