demomeetplanes.m

这是几何代数的matlab工具包

     disp('>> % |');
     % |
     disp('>> % |   MEET AND JOIN OF PLANES');
     % |   MEET AND JOIN OF PLANES
     disp('>> % |');
     % |
     clf; %/
     A = e1^(e2+0.1*e3); %/
     B = (e1+e2)^(e2+e3); %/
     draw(A,'g'); GAtext(0.35*e1+0.1*e3,'A'); %/
     draw(B,'b'); GAtext(0.6*(e2+e3),'B'); %/
     axis off; %/
     axis([-0.6 0.9 -0.6 1 -0.75 0.75]); %/
     disp('>> % |   The bivectors A and B.');
     % |   The bivectors A and B.
     disp('>> % |');
     % |
     GAprompt; %/
     GAorbiter(180,5); %/
     GAprompt; %/
     J = I3; %/
     draw(J,'y'); GAtext(0.5*(e1-e2)+0.05*e3,'J \equiv A \cup B = I_3'); %/
     axis([-0.6 0.9 -0.6 1 -0.75 0.75]); %/
     disp('>> % |  Their join is the trivector I3.');
     % |  Their join is the trivector I3.
     disp('>> % | ');
     % | 
     GAprompt; %/
     disp('>> M = inner((B/J),A)');
     M = inner((B/J),A)
     draw(M,'r'); GAtext(1.1*M,'M \equiv A \cap B = (B/I_3) \bullet A'); %/
     axis([-0.6 0.9 -0.6 1 -0.75 0.75]); %/
     disp('>> % |  Their Meet is a vector.');
     % |  Their Meet is a vector.
     disp('>> % |');
     % |
     GAprompt; %/
     GAorbiter(-180,5); %/