quartz {grDevices} R Documentation

macOS Quartz Device

Description

quartz starts a graphics device driver for the macOS system. It supports plotting both to the screen (the default) and to various graphics file formats.

Usage

quartz(title, width, height, pointsize, family, antialias, type,
file = NULL, bg, canvas, dpi)

quartz.options(..., reset = FALSE)

quartz.save(file, type = "png", device = dev.cur(), dpi = 100, ...)


Arguments

 title title for the Quartz window (applies to on-screen output only), default "Quartz %d". A C-style format for an integer will be substituted by the device number (see the file argument to postscript for further details). width the width of the plotting area in inches. Default 7. height the height of the plotting area in inches. Default 7. pointsize the default pointsize to be used. Default 12. family this is the family name of the font that will be used by the device. Default "Arial". This will be the base name of a font as shown in Font Book. antialias whether to use antialiasing. Default TRUE. type the type of output to use. See ‘Details’ for more information. Default "native". file an optional target for the graphics device. The default, NULL, selects a default name where one is needed. See ‘Details’ for more information. bg the initial background colour to use for the device. Default "transparent". An opaque colour such as "white" will normally be required on off-screen types that support transparency such as "png" and "tiff". canvas canvas colour to use for an on-screen device. Default "white", and will be forced to be an opaque colour. dpi resolution of the output. The default (NA_real_) for an on-screen display defaults to the resolution of the main screen, and to 72 dpi otherwise. See ‘Details’. ... Any of the arguments to quartz except file. reset logical: should the defaults be reset to their defaults? device device number to copy from.

Details

The defaults for all but one of the arguments of quartz are set by quartz.options: the ‘Arguments’ section gives the ‘factory-fresh’ defaults.

The Quartz graphics device supports a variety of output types. On-screen output types are "" or "native" or "Cocoa". Off-screen output types produce output files and utilize the file argument. type = "pdf" gives PDF output. The following bitmap formats may be supported (depending on the OS version): "png", "jpeg", "jpg", "jpeg2000", "tif", "tiff", "gif", "psd" (Adobe Photoshop), "bmp" (Windows bitmap), "sgi" and "pict".

The file argument is used for off-screen drawing. The actual file is only created when the device is closed (e.g., using dev.off()). For the bitmap devices, the page number is substituted if a C integer format is included in the character string, e.g. Rplot%03d.png. (The result must be less than PATH_MAX characters long, and may be truncated if not. See postscript for further details.) If a file argument is not supplied, the default is Rplots.pdf or Rplot%03d.type. Tilde expansion (see path.expand) is done.

If a device-independent R graphics font family is specified (e.g., via par(family =) in the graphics package), the Quartz device makes use of the Quartz font database (see quartzFonts) to convert the R graphics font family to a Quartz-specific font family description. The default conversions are (MonoType TrueType versions of) Helvetica for sans, Times-Roman for serif and Courier for mono.

On-screen devices are launched with a semi-transparent canvas. Once a new plot is created, the canvas is first painted with the canvas colour and then the current background colour (which can be transparent or semi-transparent). Off-screen devices have no canvas colour, and so start with a transparent background where possible (e.g., type = "png" and type = "tiff") – otherwise it appears that a solid white canvas is assumed in the Quartz code. PNG and TIFF files are saved with a dark grey matte which will show up in some viewers, including Preview.

title can be used for on-screen output. It must be a single character string with an optional integer printf-style format that will be substituted by the device number. It is also optionally used (without a format) to give a title to a PDF file.

Calling quartz() sets .Device to "quartz" for on-screen devices and to "quartz_off_screen" otherwise.

The font family chosen needs to cover the characters to be used: characters not in the font are rendered as empty oblongs. For non-Western-European languages something other than the default of "Arial" is likely to be needed—one choice for Chinese is "MingLiU".

quartz.save is a modified version of dev.copy2pdf to copy the plot from the current screen device to a quartz device, by default to a PNG file.

Conventions

This section describes the implementation of the conventions for graphics devices set out in the ‘R Internals’ manual.

• The default device size is 7 inches square.

• Font sizes are in big points.

• The default font family is Arial.

• Line widths are a multiple of 1/96 inch with no minimum set by R.

• Circle radii are real-valued with no minimum set by R.

• Colours are specified as sRGB.

Note

For a long time the default font family was documented as "Helvetica" after it had been changed to "Arial" to work around a deficiency in macOS 10.4. It may be changed back in future.

A fairly common Mac problem is no text appearing on plots due to corrupted or duplicated fonts on your system. You may be able to confirm this by using another font family, e.g. family = "serif". Open the Font Book application (in Applications) and check the fonts that you are using.

See Also

quartzFonts, Devices.

png for way to access the bitmap types of this device via R's standard bitmap devices.

Examples

## Not run:
## Only on a Mac,
## put something like this is your .Rprofile to customize the defaults
setHook(packageEvent("grDevices", "onLoad"),
function(...) grDevices::quartz.options(width = 8, height = 6,
pointsize = 10))

## End(Not run)

[Package grDevices version 4.2.0 Index]