trellis.device: Initializing Trellis Displays

Description

Initialization of a display device with appropriate graphical parameters.

Usage

trellis.device(device = getOption("device"),
               color = !(dev.name == "postscript"),
               theme = lattice.getOption("default.theme"),
               new = TRUE,
               retain = FALSE,
               ...)
standard.theme(name, color)
canonical.theme(name, color)
col.whitebg()

Arguments

Value

standard.theme returns a list of components defining graphical parameter settings for Lattice displays. It is used internally in trellis.device, and can also be used as the theme argument to trellis.par.set, or even as theme in trellis.device to use the defaults for another device. canonical.theme is an alias for standard.theme.

col.whitebg returns a similar (but smaller) list that is suitable as the theme argument to trellis.device and trellis.par.set. It contains settings values which provide colors suitable for plotting on a white background. Note that the name col.whitebg is somewhat of a misnomer, since it actually sets the background to transparent rather than white.

Details

Trellis Graphics functions obtain the default values of various graphical parameters (colors, line types, fonts, etc.) from a customizable settings list. This functionality is analogous to par for standard Rgraphics and, together with lattice.options, mostly supplants it (par settings are mostly ignored by Lattice). Unlike par, Trellis settings can be controlled separately for each different device type (but not concurrently for different instances of the same device). standard.theme and col.whitebg produce predefined settings (a.k.a. themes), while trellis.device provides a high level interface to control which theme will be in effect when a new device is opened. trellis.device is called automatically when a "trellis" object is plotted, and the defaults can be used to provide sufficient control, so in a properly configured system it is rarely necessary for the user to call trellis.device explicitly.

The standard.theme function is intended to provide device specific settings (e.g. light colors on a grey background for screen devices, dark colors or black and white for print devices) which were used as defaults prior to R2.3.0. However, these defaults are not always appropriate, due to the variety of platforms and hardware settings on which Ris used, as well as the fact that a plot created on a particular device may be subsequently used in many different ways. For this reason, a safe default is used for all devices from R2.3.0 onwards. The old behaviour can be reinstated by setting standard.theme as the default theme argument, e.g. by putting options(lattice.theme = "standard.theme") in a startup script (see the entry for theme above for details).

References

Sarkar, Deepayan (2008) "Lattice: Multivariate Data Visualization with R", Springer. http://lmdvr.r-forge.r-project.org/