disp('>> % 	INTERSECTION OF SUBSPACES');     % 	INTERSECTION OF SUBSPACES     GAfigure; clc; %/     disp('>> % 	INTERSECTION OF SUBSPACES');     % 	INTERSECTION OF SUBSPACES     disp('>> %');     %     global e P Q R S PQ RS M MM; %/     e = e3;         %/     size = 1; 	%/     IP = {e+size*(-e1-e2),e+size*(-e1+e2),e+size*(e1+e2),e+size*(e1-e2)}; %/     disp('>>      % LINE INTERSECTION AS MEET OF BIVECTORS');          % LINE INTERSECTION AS MEET OF BIVECTORS          clf; %/     disp('>> % extra dimension of the affine embedding');     % extra dimension of the affine embedding     disp('>>      e = e3;            ');          e = e3;                      draw(e,'k'); %/          GAview([30 15]); %/     	axis off; %/          DrawPolygon(IP,'w'); %/     disp('>> % points P,Q,R,S');     % points P,Q,R,S     disp('>>      P = e- e1/3+0.9*e2;    ');          P = e- e1/3+0.9*e2;              DrawHomogeneous(e,P,'n','b'); GAtext(1.07*P,'P'); %/     disp('>>      Q = e+ 0.9*e1+e2/2;    ');          Q = e+ 0.9*e1+e2/2;              DrawHomogeneous(e,Q,'n','b'); GAtext(1.07*Q,'Q'); %/     disp('>>      R = e- e1/2-e2/4;  ');          R = e- e1/2-e2/4;            DrawHomogeneous(e,R,'n','b'); GAtext(1.07*R,'R'); %/     disp('>>      S = e+ 0.9*(e1+e2);');          S = e+ 0.9*(e1+e2);          DrawHomogeneous(e,S,'n','b'); GAtext(1.07*S,'S'); %/          axis([-size size -size size (-2*size+1.2) 1.2]); %/     disp('>> % lines');     % lines     disp('>>      PQ = join(P,Q);  ');          PQ = join(P,Q);            %% DrawHomogeneous(e,PQ,'n','c'); %/     GAprompt;          DrawSimplex({P,Q},'n','c'); %/          draw(PQ,'c'); %/          axis([-size size -size size (-2*size+1.2) 1.2]); %/     disp('>>      RS = join(R,S);  ');          RS = join(R,S);            %% DrawHomogeneous(e,RS,'n','g'); %/     GAprompt;          DrawSimplex({R,S},'n','g'); %/          draw(RS,'g'); %/          axis([-size size -size size (-2*size+1.2) 1.2]); %/          GAprompt; %/     disp('>> % intersection of those lines');     % intersection of those lines     disp('>>      MM = meet(PQ,RS)       ');          MM = meet(PQ,RS)                 DrawHomogeneous(e,MM,'n','m'); %/     	draw(MM,'m'); %/     disp('>>      M = MM/inner(e,MM); ');          M = MM/inner(e,MM);           DrawHomogeneous(e,M,'n','m'); GAtext(1.07*M,'M'); %/          axis([-size size -size size (-2*size+1.2) 1.2]); %/          GAprompt; %/          GAtilt(-20,5); %/          GAtilt(40,10); %/