| trellis.par.get {lattice} | R Documentation |
These functions are used to query and modify graphical parameters for fine control of Trellis displays.
trellis.par.get(name) trellis.par.set(name, value) show.settings() trellis.settings
name |
name of a component in quotes. For possible values type
names(trellis.settings).
|
value |
desired value of the component. |
Lattice functions get their default graphical parameters from a global
variable named trellis.settings. There are a couple of settings
of this variable defined in the package, which can be set by calling
trellis.device with appropriate arguments.
The functions trellis.par.* are meant to be interfaces to this
variable. trellis.par.get returns the current value of a
particular component and trellis.par.get sets its value.
trellis.par.get is usually used inside trellis functions to get
graphical parameters before plotting. This enables device
customization as well as modifications by users via
trellis.par.set. Typical usage is:
add.line <- trellis.par.get("add.line")
add.line$col <- "red"
add.line <- trellis.par.set("add.line", add.line)
The actual list of the components in trellis.settings has not
been finalized, so I'm not attempting to list them here. The current
value can be obtained by print(trellis.settings). Most names
should be self-explanatory.
show.settings provides a graphical display summarizing some of
the values in the current setting.
There are a few more (non S compatible) interface functions which
might be simpler to use. Details can be found in the documentation for
lset.
trellis.par.get returns a list giving parameters for that
component .
S-Plus keeps a different value of the settings attached to each
device. Lattice does not work that way, and consequently sometimes the
process does not work as it should — e.g., if an x11 device is
already open with a specific (possibly modified from the default)
setting, and a call to trellis.device(postscript) is made, the
old setting will be overridden and will not be restored by
dev.off().
Deepayan Sarkar deepayan@stat.wisc.edu
show.settings()