grid (version 3.0.3)

grid.grob: Create a Grid Graphical Object

Description

These functions create grid graphical objects.

Usage

grid.grob(list.struct, cl = NULL, draw = TRUE)
grob(..., name = NULL, gp = NULL, vp = NULL, cl = NULL)
gTree(..., name = NULL, gp = NULL, vp = NULL, children = NULL, childrenvp = NULL, cl = NULL)
grobTree(..., name = NULL, gp = NULL, vp = NULL, childrenvp = NULL, cl = NULL)
childNames(gTree)
gList(...)
is.grob(x)

Arguments

...

For grob and gTree, the named slots describing important features of the graphical object. For gList and grobTree, a series of grob objects.

list.struct

a list (preferably with each element named).

name

a character identifier for the grob. Used to find the grob on the display list and/or as a child of another grob.

children

a "gList" object.

childrenvp

a viewport object (or NULL).

gp

A gpar object, typically the output from a call to the function gpar. This is basically a list of graphical parameter settings.

vp

a viewport object (or NULL).

cl

string giving the class attribute for the list.struct.

draw

logical indicating whether to produce graphical output.

gTree

a "gTree" object.

x

An R object.

Value

An R object of class "grob", a graphical object.

Details

These functions can be used to create a basic "grob", "gTree", or "gList" object, or a new class derived from one of these.

A grid graphical object (“grob”) is a description of a graphical item. These basic classes provide default behaviour for validating, drawing, and modifying graphical objects. Both call the function validDetails to check that the object returned is coherent.

A "gTree" can have other grobs as children; when a gTree is drawn, it draws all of its children. Before drawing its children, a gTree pushes its childrenvp slot and then navigates back up (calls upViewport) so that the children can specify their location within the childrenvp via a vpPath.

Grob names need not be unique in general, but all children of a gTree must have different names. A grob name can be any string, though it is not advisable to use the gPath separator (currently ::) in grob names.

The function childNames returns the names of the grobs which are children of a gTree.

All grid primitives (grid.lines, grid.rect, ...) and some higher-level grid components (e.g., grid.xaxis and grid.yaxis) are derived from these classes.

grobTree is just a convenient wrapper for gTree when the only components of the gTree are grobs (so all unnamed arguments become children of the gTree).

grid.grob is deprecated.

See Also

grid.draw, grid.edit, grid.get.