function draw(s,O,c)%draw(s,O,c) - draw a multivector. %  s: the multivector to be drawn.%  O: an offset by which to displace the multivector before drawing (optional)%  c: a color in which to draw the multivector (optional).%%  For bivectors, can set shape using 'GAbvShape'%%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.set(gcf,'Render',GArender)A = GAZ(s);% if you assign to nargin, then Matlab doesn't set it% We will set na to be 2 (no color) or 3 (color)na = nargin;	if nargin == 1    O = GA([0;0;0;0;0;0;0;0]);    na = 2;elseif nargin == 2    if isa(O,'char')       c = O;       O = GA([0;0;0;0;0;0;0;0]);       na = 3;    endendif isa(A,'double')     if nargin == 2     title(['scalar = ' num2str(A)]);    else     title(['scalar = ' num2str(A)], 'Color', c);    end    hold on;elseif GAisa(A,'double')    if nargin == 2     title(['scalar = ' num2str(A.m(1))]);    else     title(['scalar = ' num2str(A.m(1))], 'Color', c);    end    hold on;elseif GAisa(A,'vector')     if na == 2	arrow(A,O);     else	arrow(A,O,c);     end     hold on;elseif GAisa(A,'bivector')     if na == 2	drawBivector(A,O);     else        drawBivector(A,O,c);     endelseif GAisa(A,'trivector')     if na == 2        drawTrivector(A,O);     else        drawTrivector(A,O,c);     endelse     % Draw a multivector as the sum of its parts     if sum(abs(A.m(2:4))) > 0          M = GA([0; A.m(2:4); 0; 0; 0; 0]);	  if na == 3	    draw(M,O,c);    	  else	    draw(M,O);	  end     end     if sum(abs(A.m(5:7))) > 0          M = GA([0; 0; 0; 0; A.m(5:7); 0]);	  if na == 3	    draw(M,O,c);    	  else	    draw(M,O);	  end     end     if A.m(8) ~= 0          M = GA([0; 0; 0; 0; 0; 0; 0; A.m(8)]);	  if na == 3	    draw(M,O,c);    	  else	    draw(M,O);	  end     end     if A.m(1) ~= 0	  if na == 3	    draw(A.m(1),O,c);    	  else	    draw(A.m(1),O);	  end     end     return;	% Return to avoid 2 'axis' callsend% We want equal axes to avoid distortion.  However, we need% the axis('auto') before hand to ensure that everything% appears on the screen.axis('auto');axis('equal');axis('tight');