LINEPOSITION Position of a point on a line.

   POS = linePosition(POINT, LINE);
   Computes position of point POINT on the line LINE, relative to origin
   point and direction vector of the line.
   LINE has the form [x0 y0 dx dy],
   POINT has the form [x y], and is assumed to belong to line.

   POS = linePosition(POINT, LINES);
   If LINES is an array of NL lines, return NL positions, corresponding to
   each line.

   POS = linePosition(POINTS, LINE);
   If POINTS is an array of NP points, return NP positions, corresponding
   to each point.

   POS = linePosition(POINTS, LINES);
   If POINTS is an array of NP points and LINES is an array of NL lines,
   return an array of [NP NL] position, corresponding to each couple
   point-line.

   POS = linePosition(POINTS, LINES, 'diag');
   When POINTS and LINES have the same number of rows, computes positions
   only for couples POINTS(i,:) and LINES(i,:). The result POS is a column
   vector with as many rows as the number of points/lines.


   Example
   line = createLine([10 30], [30 90]);
   linePosition([20 60], line)
   ans =
       .5

   See also:
   lines2d, createLine, projPointOnLine, isPointOnLine

   ---------

   author : David Legland 
   INRA - TPV URPOI - BIA IMASTE
   created the 25/05/2004.

Package: matgeom