R: Initializing Trellis Displays

trellis.device {lattice}

R Documentation

Initializing Trellis Displays

Description

trellis.device initializes a Trellis display device with appropriate settings of the graphics control parameter trellis.settings.

Usage

trellis.device(device = getOption("device"),
               color = !(dev.name == "postscript"),
               theme = getOption("lattice.theme"),
               bg = NULL,
               new = TRUE,
               retain = FALSE,
               ...)
canonical.theme(name, color)

Arguments

`device`	name of a function (possibly as a character string) that initializes a device. Admissible values include "x11", "windows", "mac", "postscript", "pdf", "png", etc.
`color`	logical, whether the display should be color or black and white. `FALSE` for postscript devices, `TRUE` otherwise.
`theme`	list of components that change the settings of the device opened, or, a function that when called produces such a list. The function name can be supplied as a quoted string. A possible use of this argument is to change the default settings at session startup, for example by setting `options(lattice.theme = "col.whitebg")`. If `theme` is a function, it will not be supplied any arguments, however, it is guaranteed that a device will already be open when it is called, so one may use `.Device` inside the function to ascertain what device has been opened.
`bg`	background color for the device.
`new`	logical flag indicating whether a new device should be started. If `FALSE`, the options for the current device are changed to the defaults determined by the other arguments.
`retain`	logical. If `TRUE` and a setting for this device already exists, then that is used instead of the defaults for this device. By default, pre-existing settings are overwritten (and lost).
`name`	name of the device for which the setting is required, as returned by `.Device`
`...`	additional parameters to be passed to the `device` function, most commonly `file` for non-screen devices.

Details

trellis.device calls the device function to start a display, and sets an appropriate component of the variable lattice.theme (in an unexported environment named .LatticeEnv) to appropriate (device-specific) values.

The device specific settings are determined by canonical.theme which returns a list (see below).

The settings can subsequently be handled by the interface functions trellis.par.get, trellis.par.set and lset

Value

canonical.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 an argument to lset, or even as theme in trellis.device to use the defaults for another device.

Author(s)

Deepayan Sarkar deepayan@stat.wisc.edu