grid.circle {grid} | R Documentation |
Functions to create and draw a circle.
grid.circle(x=0.5, y=0.5, r=0.5, default.units="npc", name=NULL, gp=gpar(), draw=TRUE, vp=NULL) circleGrob(x=0.5, y=0.5, r=0.5, 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. |
r |
A numeric vector or unit object specifying radii. |
default.units |
A string indicating the default units to use
if |
name |
A character identifier. |
gp |
An object of class |
draw |
A logical value indicating whether graphics output should be produced. |
vp |
A Grid viewport object (or NULL). |
Both functions create a circle grob (a graphical object describing a
circle), but only grid.circle()
draws the circle (and then only if draw
is TRUE
).
The radius may be given in any
units; if the units are relative (e.g., "npc"
or
"native"
) then the radius will be different depending on
whether it is interpreted as a width or as a height. In such cases,
the smaller of these two values will be the result. To see the
effect, type grid.circle()
and adjust the size of the window.
What happens for very small radii is device-dependent: the circle may become invisible or be shown at a fixed minimum size. Circles of zero radius will not be plotted.
A circle grob. grid.circle()
returns the value invisibly.
Negative values for the radius are silently converted to their absolute value.
Paul Murrell