function DrawPolyline(P,c)% DrawPolyline(P,c) - draw a polyline along the tips of the vector arguments%  P: a cell array of GA vectors%  c: an optional color argument%%See also gable.% GABLE, Copyright (c) 1999, University of Amsterdam% Copying, use and development for non-commercial purposes permitted.%          All rights for commercial use reserved; for more information%          contact Leo Dorst (leo@wins.uva.nl).%%          This software is unsupported.l = length(P);if l < 2	error('DrawPolyline: requires at least two vector arguments');endif nargin == 1     c = 'b';elseif nargin > 2     error('DrawPolyline: takes only 2 arguments');endx = zeros(1,l);y = zeros(1,l);z = zeros(1,l);for i = 1:l	v = m(GA(P{i}));        if ~GAisa(GAZ(P{i}),'vector')                error('DrawPolyline: all objects in P must be vectors.');        end	x(i) = v(2);	y(i) = v(3);	z(i) = v(4);endplot3(x,y,z,c);hold on;axis('equal');