Low-level Options Controlling Behaviour of Lattice
Functions to handle settings used by lattice. Their main purpose is to make code maintainance easier, and users normally should not need to use these functions. However, fine control at this level maybe useful in certain cases.
character giving the name of a setting
new options can be defined, or existing ones modified, using one or
more arguments of the form
These functions are modeled on
and behave similarly for the most part. Some of the available
components are documented here, but not all. The purpose of the ones
not documented are either fairly obvious, or not of interest to the
A function, or
NULL. If the former, every call to the panel function will be wrapped inside
tryCatchwith the specified function as an error handler. The default is to use the
panel.errorfunction. This prevents the plot from failing due to errors in a single panel, and leaving the grid operations in an unmanageable state. If set to
NULL, errors in panel functions will not be caught using
Logical flag indicating whether a
"trellis"object should be saved when plotted for subsequent retrieval and further manipulation. Defaults to
Controls details of the default space allocation in the grid layout created in the course of plotting a
"trellis"object. Each named component is a list of arguments to the grid function
units, and optionally
Usually not of interest to the end-user, who should instead use the similiarly named component in the graphical settings, modifiable using
A list of two components named
data, both logical flags. The flags indicate whether the unused levels of factors (conditioning variables and primary variables respectively) will be dropped, which is usually relevant when a subsetting operation is performed or an 'interaction' is created. See
xyplotfor more details. Note that this does not control dropping of levels of the 'groups' argument.
A character string, either
"panel". This determines the interpretation of
key(determining the legend; see
xyplot): either the full figure region ('"full"'), or just the region that bounds the panels and strips ('"panel"').
A list giving default values for various standard arguments:
A list giving arguments to
gparused to highlight a viewport chosen using
The banking function. See
List with components named
"factor", both scalar numbers. Panel limits are extended by this amount, to provide padding for numeric and factor scales respectively. The value for numeric is multiplicative, whereas factor is additive.
Numeric scalar between 0 and 1. Tick marks that are too close to the limits are not drawn unless explicitly requested. The limits are contracted by this proportion, and anything outside is skipped.
The separator for creating interactions with the extended formula interface (see
List determining default units for axis components. Should not be of interest to the end-user.
In addition, there is an option for the default prepanel and panel
function for each high-level function; e.g.,
xyplot. The options
for the others have similarly patterned names.
lattice.getOption returns the value of a single component,
lattice.options always returns a list with one or more
named components. When changing the values of components, the old
values of the modified components are returned by
lattice.options. If called without any arguments, the full
list is returned.
Deepayan Sarkar Deepayan.Sarkar@R-project.org