grid.null {grid}

R Documentation

Null Graphical Object

Description

These functions create a NULL graphical object, which has zero width, zero height, and draw nothing. It can be used as a place-holder or as an invisible reference point for other drawing.

Usage

nullGrob(x = unit(0.5, "npc"), y = unit(0.5, "npc"),
         default.units = "npc",
         name = NULL, vp = NULL)
grid.null(...)

Arguments

x	A numeric vector or unit object specifying x-location.
y	A numeric vector or unit object specifying y-location.
default.units	A string indicating the default units to use if x, y, width, or height are only given as numeric vectors.
name	A character identifier.
vp	A Grid viewport object (or NULL).
...	Arguments passed to nullGrob().

Value

A null grob.

Author(s)

Paul Murrell

See Also

Grid, viewport

Examples

grid.newpage()
grid.null(name="ref")
grid.rect(height=grobHeight("ref"))
grid.segments(0, 0, grobX("ref", 0), grobY("ref", 0))

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