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<p>
Next: <a rel="next" accesskey="n" href="Identifying-Points-in-Triangulation.html#Identifying-Points-in-Triangulation">Identifying Points in Triangulation</a>,
Up: <a rel="up" accesskey="u" href="Delaunay-Triangulation.html#Delaunay-Triangulation">Delaunay Triangulation</a>
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<h4 class="subsection">30.1.1 Plotting the Triangulation</h4>
<p>Octave has the functions <code>triplot</code>, <code>trimesh</code>, and <code>trisurf</code>
to plot the Delaunay triangulation of a 2-dimensional set of points.
<!-- triplot scripts/plot/triplot.m -->
<p><a name="doc_002dtriplot"></a>
<div class="defun">
— Function File: <b>triplot</b> (<var>tri, x, y</var>)<var><a name="index-triplot-2782"></a></var><br>
— Function File: <b>triplot</b> (<var>tri, x, y, linespec</var>)<var><a name="index-triplot-2783"></a></var><br>
— Function File: <var>h</var> = <b>triplot</b> (<var><small class="dots">...</small></var>)<var><a name="index-triplot-2784"></a></var><br>
<blockquote><p>Plot a triangular mesh in 2D. The variable <var>tri</var> is the triangular
meshing of the points <code>(</code><var>x</var><code>, </code><var>y</var><code>)</code> which is returned from
<code>delaunay</code>. If given, <var>linespec</var> determines the properties
to use for the lines.
<p>The optional return value <var>h</var> is a graphics handle to the created plot.
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<p class="noindent"><strong>See also:</strong> <a href="doc_002dplot.html#doc_002dplot">plot</a>, <a href="doc_002dtrimesh.html#doc_002dtrimesh">trimesh</a>, <a href="doc_002dtrisurf.html#doc_002dtrisurf">trisurf</a>, <a href="doc_002ddelaunay.html#doc_002ddelaunay">delaunay</a>.
</p></blockquote></div>
<!-- trimesh scripts/plot/trimesh.m -->
<p><a name="doc_002dtrimesh"></a>
<div class="defun">
— Function File: <b>trimesh</b> (<var>tri, x, y, z</var>)<var><a name="index-trimesh-2785"></a></var><br>
— Function File: <var>h</var> = <b>trimesh</b> (<var><small class="dots">...</small></var>)<var><a name="index-trimesh-2786"></a></var><br>
<blockquote><p>Plot a triangular mesh in 3D. The variable <var>tri</var> is the triangular
meshing of the points <code>(</code><var>x</var><code>, </code><var>y</var><code>)</code> which is returned
from <code>delaunay</code>. The variable <var>z</var> is value at the point
<code>(</code><var>x</var><code>, </code><var>y</var><code>)</code>.
<p>The optional return value <var>h</var> is a graphics handle to the created plot.
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<p class="noindent"><strong>See also:</strong> <a href="doc_002dtriplot.html#doc_002dtriplot">triplot</a>, <a href="doc_002dtrisurf.html#doc_002dtrisurf">trisurf</a>, <a href="doc_002ddelaunay3.html#doc_002ddelaunay3">delaunay3</a>.
</p></blockquote></div>
<!-- trisurf scripts/plot/trisurf.m -->
<p><a name="doc_002dtrisurf"></a>
<div class="defun">
— Function File: <b>trisurf</b> (<var>tri, x, y, z</var>)<var><a name="index-trisurf-2787"></a></var><br>
— Function File: <var>h</var> = <b>trisurf</b> (<var><small class="dots">...</small></var>)<var><a name="index-trisurf-2788"></a></var><br>
<blockquote><p>Plot a triangular surface in 3D. The variable <var>tri</var> is the triangular
meshing of the points <code>(</code><var>x</var><code>, </code><var>y</var><code>)</code> which is returned
from <code>delaunay</code>. The variable <var>z</var> is value at the point
<code>(</code><var>x</var><code>, </code><var>y</var><code>)</code>.
<p>The optional return value <var>h</var> is a graphics handle to the created plot.
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<p class="noindent"><strong>See also:</strong> <a href="doc_002dtriplot.html#doc_002dtriplot">triplot</a>, <a href="doc_002dtrimesh.html#doc_002dtrimesh">trimesh</a>, <a href="doc_002ddelaunay3.html#doc_002ddelaunay3">delaunay3</a>.
</p></blockquote></div>
<p>The difference between <code>triplot</code>, and <code>trimesh</code> or <code>triplot</code>,
is that the former only plots the 2-dimensional triangulation itself, whereas
the second two plot the value of a function <code>f (</code><var>x</var><code>, </code><var>y</var><code>)</code>. An
example of the use of the <code>triplot</code> function is
<pre class="example"> rand ("state", 2)
x = rand (20, 1);
y = rand (20, 1);
tri = delaunay (x, y);
triplot (tri, x, y);
</pre>
<p class="noindent">which plots the Delaunay triangulation of a set of random points in
2-dimensions.
The output of the above can be seen in <a href="fig_003atriplot.html#fig_003atriplot">fig:triplot</a>.
<div class="float">
<a name="fig_003atriplot"></a><div align="center"><img src="triplot.png" alt="triplot.png"></div>
<p><strong class="float-caption">Figure 30.2: Delaunay triangulation of a random set of points</strong></p></div>
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