%% slight cheat, since I set J = I3 explicilty%% so merely for illustration of the principle%% should actually allow line to in plane as well% |% |   MEET AND JOIN OF LINE AND PLANE % |clf; %/A = e1+e3; %/A=A/norm(A); %/B = (e1+e2)^(e2+e3); %/B =B/norm(B); %/draw(A,'m'); GAtext(1.1*A,'A'); %/draw(B,'c'); GAtext(0.45*(e2+e3),'B'); %/axis off; %/axis([-0.7 0.7 -0.7 0.7 -0.75 0.75]); %/% |% |   The line A and plane B.% |GAprompt; %/GAorbiter(40,5); %/GAprompt; %/J = I3; %/draw(J,'y'); GAtext(0.5*(e1-e2)+0.05*I3,'J \equiv A \cup B = I_3'); %/axis([-0.7 0.7 -0.7 0.7 -0.75 0.75]); %/% |% |  Their join is the trivector I3.% | GAprompt; %/M = inner((B/J),A) %/DrawPoint({0},'r',20); %/GAtext(0.1*e1,'M \equiv A \cap B = scalar'); %/axis([-0.7 0.7 -0.7 0.7 -0.75 0.75]); %/% |% |  Their Meet is a scalar, representing the point at the origin.% |GAprompt; %/GAorbiter(-30,5); %/