Initializing Trellis Displays
Initialization of a display device with appropriate graphical parameters.
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()
- function (or the name of one as a character string)
that starts a device. Admissible values depend on the platform and
how R was compiled (see
Devices), but usually
"jpeg"and at least one of
"quartz"will be available.
- logical, whether the initial settings should be color or
black and white. Defaults to
FALSEfor postscript devices,
TRUEotherwise. Note that this only applies to the initial choice of colors, which can be overridden using
themeor subsequent calls to
trellis.par.set(and by arguments supplied directly in high level calls for some settings).
- list of components that changes 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. These
settings are only used to modify the default settings (determined by
other arguments), and need not contain all possible parameters.
A possible use of this argument is to change the default settings by specifying
lattice.options(default.theme = "col.whitebg"). For back-compatibility, this is initially (when lattice is loaded) set to
themeis 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
.Deviceinside the function to ascertain what device has been opened.
- logical flag indicating whether a new device should be
FALSE, the options for the current device are changed to the defaults determined by the other arguments.
TRUEand 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 of the device for which the setting is required, as
- additional parameters to be passed to the
devicefunction, most commonly
filefor non-screen devices, as well as
width, etc. See the help file for individual devices for admissible arguments.
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
par for standard R graphics and, together with
lattice.options, mostly supplants it (
settings are mostly ignored by Lattice). Unlike
Trellis settings can be controlled separately for each different
device type (but not concurrently for different instances of the same
predefined settings (a.k.a. themes), while
provides a high level interface to control which theme will
be in effect when a new device is opened.
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
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 R 2.3.0. However, these defaults are not
always appropriate, due to the variety of platforms and hardware
settings on which R is 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 R 2.3.0 onwards. The old behaviour can be reinstated by
standard.theme as the default
e.g. by putting
"standard.theme") in a startup script (see the entry for
above for details).
standard.themereturns 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
trellis.par.set, or even as
trellis.deviceto use the defaults for another device.
canonical.themeis an alias for
col.whitebgreturns a similar (but smaller) list that is suitable as the
trellis.par.set. It contains settings values which provide colors suitable for plotting on a white background. Note that the name
col.whitebgis somewhat of a misnomer, since it actually sets the background to transparent rather than white.
Earlier versions of
trellis.device had a
bg argument to
set the background color, but this is no longer supported. If
bg argument will be passed on to the device
function; however, this will have no effect on the Trellis settings.
It is rarely meaningful to change the background alone; if you feel
the need to change the background, consider using the
Sarkar, Deepayan (2008) Lattice: Multivariate Data Visualization with R, Springer. http://lmdvr.r-forge.r-project.org/
trellis.par.set can be
used to query and modify the settings after a device has been
par.settings argument to high level
functions, described in
xyplot, can be used to attach
transient settings to a