function b = DrawBivector(A,B,c)% DrawBivector(A,B,c) : draw the bivector A^B.  %  A and B must be vectors.  c is 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.if nargin == 2    c = 'y';endA = GAZ(A);B = GAZ(B);if ~GAisa(A,'vector') | ~GAisa(B,'vector')    A    B    error('DrawBivector: A and B must both be vectors.');end% DrawBivector: draw the parallelogram bounded by A,B.X = [0 A.m(2) A.m(2)+B.m(2) B.m(2)];Y = [0 A.m(3) A.m(3)+B.m(3) B.m(3)];Z = [0 A.m(4) A.m(4)+B.m(4) B.m(4)];biarrow(B,A,'g');patch(X,Y,Z,c);draw(A);b = A^B;