disp('>> %	ROTATION BY ROTORS');     %	ROTATION BY ROTORS     GAfigure; clc; %/     disp('>> %	ROTATION BY ROTORS');     %	ROTATION BY ROTORS     global plane angle i phi Raxis; %/     clf; %/     disp('>> %');     %     disp('>> % 	Making a rotor:');     % 	Making a rotor:     disp('>> %');     %     disp('>> plane = e1^e2;');     plane = e1^e2;     disp('>> angle = pi/4;');     angle = pi/4;     i = plane; %/     phi = angle; %/     fprintf(1,'>> R = gexp(-plane*angle/2)   ');     input('');     R = gexp(-plane*angle/2) %w %%     GAprompt;     disp('>> % 	Applying the rotor:');     % 	Applying the rotor:     disp('>> x = e1 + e3;');     x = e1 + e3;     draw(x,'r'); %/     axis([-1 1 -1 1 -1 1]); %/     axis off; %/     GAtext(0.7*x+0.1*unit(grade(inner(x,plane)/plane,1)),'x'); %/     draw(plane*angle); %/     GAview([15 30]); %/     axis([-1 1 -1 1 -1 1]); %/     GAtext(0.1*plane/I3-0.3*unit(grade(inner(x,plane)/plane,1)),'i \phi'); %/     fprintf(1,'>> r = R*x/R  ');     input('');     r = R*x/R %w     draw(r,'m'); %/     axis([-1 1 -1 1 -1 1]); %/     title(['rotor R = e^{-i \phi /2}'],'Color','b'); %/     GAtext(0.9*r+0.1*unit(grade(inner(r,plane)/plane,1)),'R x R^{-1}'); %/     GAprompt; %/     title(''); %/     GAorbiter(-360,5); %/     disp('>> % In 3-space, you could characterize the rotation by an axis:');     % In 3-space, you could characterize the rotation by an axis:     fprintf(1,'>> Raxis = plane/I3  ');     input('');     Raxis = plane/I3 %w     draw(Raxis,'k'); %/     axis([-1 1 -1 1 -1 1]); %/     GAtext(1.1*Raxis,'i \phi / I_3'); %/     GAprompt; %/     disp('>> % Now rotate a bivector.');     % Now rotate a bivector.     disp('>> B = 0.7*x^(e1+e2);');     B = 0.7*x^(e1+e2);     draw(B,'w'); %/     axis([-1 1 -1 1 -1 1]); %/     Blabel = -0.75*unit(meet(B,i)); %/     GAtext(Blabel,'B'); %/     fprintf(1,'>> RB = R*B/R  ');     input('');     RB = R*B/R %w     draw(RB,'y'); %/     axis([-1 1 -1 1 -1 1]); %/     GAtext(R*Blabel/R,'R B R^{-1}'); %/     GAprompt; %/     GAorbiter(-400,10); %/