l: david.legland@grignon.inra.fr</span>
<span class="comment">% Created: 2009-06-22,    using Matlab 7.7.0.471 (R2008b)</span>
<span class="comment">% Copyright 2009 INRA - Cepia Software Platform.</span>
</pre><h2>Create points and lines<a name="3"></a></h2><pre class="codeinput"><span class="comment">% create some points: points are simply represented by a row vector of 3</span>
<span class="comment">% elements.</span>
p1 = [10 20 30];
p2 = [80 10 20];
p3 = [20 50 10];

<span class="comment">% points can 