ints, edges, lines and plane</span>
<span class="comment">%   - draw these shape on current figure</span>
<span class="comment">%   - compute intersections of lines and planes</span>
<span class="comment">%   - compute lines perpendicular to a plane</span>
<span class="comment">%</span>
<span class="comment">%   See also</span>
<span class="comment">%</span>
<span class="comment">%</span>
<span class="comment">% ------</span>
<span class="comment">% Author: David Legland</span>
<span class="comment">% e-mai