| grid.polygon {grid} | R Documentation | 
These functions create and draw a polygon. The final point will automatically be connected to the initial point.
grid.polygon(x=c(0, 0.5, 1, 0.5), y=c(0.5, 1, 0.5, 0),
             id=NULL, id.lengths=NULL,
             default.units="npc", name=NULL,
             gp=gpar(), draw=TRUE, vp=NULL)
polygonGrob(x=c(0, 0.5, 1, 0.5), y=c(0.5, 1, 0.5, 0),
             id=NULL, id.lengths=NULL,
             default.units="npc", name=NULL,
             gp=gpar(), vp=NULL)
x | 
A numeric vector or unit object specifying x-locations. | 
y | 
A numeric vector or unit object specifying y-locations. | 
id | 
A numeric vector used to separate locations in x and
y into multiple polygons.  All locations with the same
id belong to the same polygon. | 
id.lengths | 
A numeric vector used to separate locations in x and
y into multiple polygons.  Specifies consecutive blocks of
locations which make up separate polygons. | 
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. | 
gp | 
An object of class gpar, typically the output
from a call to the function gpar.  This is basically
a list of graphical parameter settings. | 
draw | 
A logical value indicating whether graphics output should be produced. | 
vp | 
A Grid viewport object (or NULL). | 
Both functions create a polygon grob (a graphical object describing a
polygon), but only grid.polygon
draws the polygon (and then only if draw is TRUE).
A grob object.
Paul Murrell
grid.polygon()
# Using id (NOTE: locations are not in consecutive blocks)
grid.newpage()
grid.polygon(x=c((0:4)/10, rep(.5, 5), (10:6)/10, rep(.5, 5)),
             y=c(rep(.5, 5), (10:6/10), rep(.5, 5), (0:4)/10),
             id=rep(1:5, 4),
             gp=gpar(fill=1:5))
# Using id.lengths
grid.newpage()
grid.polygon(x=outer(c(0, .5, 1, .5), 5:1/5),
             y=outer(c(.5, 1, .5, 0), 5:1/5),
             id.lengths=rep(4, 5),
             gp=gpar(fill=1:5))