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<table width="100%" summary="page for grid.circle {grid}"><tr><td>grid.circle {grid}</td><td align="right">R Documentation</td></tr></table>
<h2>Draw a Circle</h2>


<h3>Description</h3>

<p>
Functions to create and draw a circle.
</p>


<h3>Usage</h3>

<pre>
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)
</pre>


<h3>Arguments</h3>

<table summary="R argblock">
<tr valign="top"><td><code>x</code></td>
<td>
A numeric vector or unit object specifying x-locations.</td></tr>
<tr valign="top"><td><code>y</code></td>
<td>
A numeric vector or unit object specifying y-locations.</td></tr>
<tr valign="top"><td><code>r</code></td>
<td>
A numeric vector or unit object specifying radii.</td></tr>
<tr valign="top"><td><code>default.units</code></td>
<td>
A string indicating the default units to use
if <code>x</code>, <code>y</code>, <code>width</code>, or <code>height</code>
are only given as numeric vectors.</td></tr>
<tr valign="top"><td><code>name</code></td>
<td>
A character identifier. </td></tr>
<tr valign="top"><td><code>gp</code></td>
<td>
An object of class <code>gpar</code>, typically the output
from a call to the function <code>gpar</code>.  This is basically
a list of graphical parameter settings.</td></tr>
<tr valign="top"><td><code>draw</code></td>
<td>
A logical value indicating whether graphics output
should be produced.</td></tr>
<tr valign="top"><td><code>vp</code></td>
<td>
A Grid viewport object (or NULL).</td></tr>
</table>

<h3>Details</h3>

<p>
Both functions create a circle grob (a graphical object describing a
circle), but only <code>grid.circle()</code>
draws the circle (and then only if <code>draw</code> is <code>TRUE</code>).
</p>
<p>
The radius may be given in any
units;  if the units are <EM>relative</EM> (e.g., <code>"npc"</code> or
<code>"native"</code>) 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 <code>grid.circle()</code> and adjust the size of the window.
</p>


<h3>Value</h3>

<p>
A circle grob.  <code>grid.circle()</code> returns the value invisibly.</p>

<h3>Warning</h3>

<p>
Negative values for the radius are silently converted to their
absolute value.
</p>


<h3>Author(s)</h3>

<p>
Paul Murrell
</p>


<h3>See Also</h3>

<p>
<a href="Grid.html">Grid</a>,
<code><a href="viewport.html">viewport</a></code>
</p>



<hr><div align="center">[Package <em>grid</em> version 2.5.1 <a href="00Index.html">Index]</a></div>

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