gcd(z1,z2) , lcm(z1,z2)
axis([-7 14 0 21]) ; axis square
1*-1 + 1*1 = 0
Pl2 = [0 1 0 0 0; 0 0 0 0 1; 0 0 0 0 0; 0 0 0 0 0; 1 0 0 0 0]
Pr2 = [0 0 1 0 0; 0 1 0 0 0; 0 0 0 0 0; 1 0 0 0 0; 0 0 0 0 0]
M= [-6 6 4]'
en = [0.6 0 0.8]
T1 = [1 0 -4; 0 1 -6;0 0 1]; T2 = [0 -1 0; 1 0 0 ; 0 0 1]; T3 = [1 0 4; 0 1 6;0 0 1]; TT = T3*T2*T1 % =[0 -1 10; 1 0 2 ; 0 0 1]; Q = [-2 4 4 -2 -2; 6 6 12 12 6; 1 1 1 1 1]; QT = TT*Q; plot(Q(1,:),Q(2,:)); hold on; plot(QT(1,:),QT(2,:),'r'); axis([-15 15 -15 15]); axis square; hold off
w=(0:0.02:5)*2*pi; y= 8*cos(w); z= 8*sin(w); xr= w*1.2/2/pi; xl = -xr; clf; plot3(xr,y,z); hold on; plot3(xl,y,z,'m'); axis equal; hold off