CREATEEDGE Create an edge between two points, or from a line.

   The internal format for edge representation is given by coordinates of
   two points : [x1 y1 x2 y2].
   This function can serve as a line to edge converter.


   E = createEdge(P1, P2);
   Returns the edge between the two given points P1 and P2.
   
   E = createEdge(x0, y0, dx, dy);
   Returns the edge going through point (x0, y0) and with direction
   vector (dx,dy).

   E = createEdge(param);
   where param is an array of 4 values, creates the edge going through the
   point (param(1) param(2)), and with direction vector given by
   (param(3) param(4)).
   
   E = createEdge(LINE, D);
   create the edge contained in LINE, with same direction and start point,
   but with length given by D.


   Note: in all cases, parameters can be vertical arrays of the same
   dimension. The result is then an array of edges, of dimensions N-by-4.


   See also:
   edges2d, lines2d, drawEdge, clipEdge, createLine

Package: matgeom