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<h2>4. Sizes and Spacing
<a name="4. Sizes and Spacing"></a>
</h2>
<p style="margin-top: 1em">Sizes are specified in inches.
If you don’t like inches, it’s possible to set a
global style variable <b>scale</b> that changes the unit.
Setting <b>scale = 2.54</b> effectively changes the internal
unit to centimeters (all other size variable values are
scaled correspondingly).</p>
<h3>4.1. Default Sizes of Objects
<a name="4.1. Default Sizes of Objects"></a>
</h3>
<p style="margin-top: 1em">Here are the default sizes for
<b>pic</b> objects:</p>
<p align="center"><img src="img/pic8.png" alt="Image img/pic8.png"></p>
<p>The simplest way to think about these defaults is that
they make the other basic objects fit snugly into a
default-sized box.</p>
<p style="margin-top: 1em"><i>pic2plot</i>(1) does not
necessarily emit a physical inch for each virtual inch in
its drawing coordinate system. Instead, it draws on a canvas
8 virtual inches by 8 virtual inches wide. If its
output page size is “letter”, these virtual
inches will map to real ones. Specifying a different page
size (such as, say, “a4”) will scale virtual
inches so they are output as one eighth of the page width.
Also, <i>pic2plot</i>(1) centers all images by default,
though the <b>−n</b> option can be used to prevent
this.</p>
<h3>4.2. Objects Do Not Stretch!
<a name="4.2. Objects Do Not Stretch!"></a>
</h3>
<p style="margin-top: 1em">Text is rendered in the current
font with normal troff line spacing. Boxes, circles, and
ellipses do <i>not</i> automatically resize to fit enclosed
text. Thus, if you say <b>box "this text far too long
for a default box"</b> you’ll get this:</p>
<p align="center" style="margin-top: 1em"><img src="img/pic9.png" alt="Image img/pic9.png"></p>
<p align="center" style="margin-top: 1em">Figure 4-1: Boxes
do not automatically resize</p>
<p style="margin-top: 1em">which is probably not the effect
you want.</p>
<h3>4.3. Resizing Boxes
<a name="4.3. Resizing Boxes"></a>
</h3>
<p style="margin-top: 1em">To change the box size, you can
specify a box width with the “width”
modifier:</p>
<p align="center" style="margin-top: 1em"><img src="img/pic10.png" alt="Image img/pic10.png"></p>
<p align="center" style="margin-top: 1em">Figure 4-2:
Result of <b>box width 3</b></p>
<p style="margin-top: 1em">This modifier takes a dimension
in inches. There is also a “height” modifier
that changes a box’s height. The <b>width</b> keyword
may be abbreviated to <b>wid</b>; the <b>height</b> keyword
to <b>ht</b>.</p>
<h3>4.4. Resizing Other Object Types
<a name="4.4. Resizing Other Object Types"></a>
</h3>
<p style="margin-top: 1em">To change the size of a circle,
give it a <b>rad[ius]</b> or <b>diam[eter]</b> modifier;
this changes the radius or diameter of the circle, according
to the numeric argument that follows.</p>
<p align="center" style="margin-top: 1em"><img src="img/pic11.png" alt="Image img/pic11.png"></p>
<p align="center" style="margin-top: 1em">Figure 4-3:
Circles with increasing radii</p>
<p style="margin-top: 1em">The <b>move</b> command can also
take a dimension, which just tells it how many inches to
move in the current direction.</p>
<p style="margin-top: 1em">Ellipses are sized to fit in the
rectangular box defined by their axes, and can be resized
with <b>width</b> and <b>height</b> like boxes.</p>
<p style="margin-top: 1em">You can also change the radius
of curvature of an arc with <b>rad[ius]</b> (which specifies
the radius of the circle of which the arc is a segment).
Larger values yield flatter arcs.</p>
<p align="center" style="margin-top: 1em"><img src="img/pic12.png" alt="Image img/pic12.png"></p>
<p align="center" style="margin-top: 1em">Figure 4-4:
<b>arc rad</b> with increasing radii</p>
<p style="margin-top: 1em">Observe that because an arc is
defined as a quarter circle, increasing the radius also
increases the size of the arc’s bounding box.</p>
<h3>4.5. The ‘same’ Keyword
<a name="4.5. The ‘same’ Keyword"></a>
</h3>
<p style="margin-top: 1em">In place of a dimension
specification, you can use the keyword <b>same</b>. This
gives the object the same size as the previous one of its
type. As an example, the program</p>
<pre style="margin-left:10%; margin-top: 1em">.PS
box; box wid 1 ht 1; box same; box
.PE</pre>
<p style="margin-top: 1em">gives you</p>
<p align="center" style="margin-top: 1em"><img src="img/pic13.png" alt="Image img/pic13.png"></p>
<p align="center" style="margin-top: 1em">Figure 4-5: The
<b>same</b> keyword</p>
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