Vectors must be same lenght

Hi , i've been trying to graph a mechanism degree move from 220 to 270 but i get the error how can i solve ?

AB=200;
BC=480;
CD=480;
DQ=450;
AQ=480;
FB=100;
DE=600;
AF=300;
ED=600;
DC=CD;
x=AQ;
y=DQ;
a2=CD;
a3=BC;
a4=AB;
a1=-x-y;
k1=a1/a2;
k2=a1/a4;
k3=(a1^2+a2^2-a3^2+a4)/((2*a4^2)*a2);

n=1;
theta=220;
while ((theta>=220)&&(theta<=270))
    tht(n)=(theta+210)*(pi/180);
    K=(-a3^2+a1^2+a4^2+a2^2);
    X1=k1*cos(tht(n));
    Y1=k2*cos(tht(n));
    A=cos(tht(n))*(1-k2)+k3-k1;
    B=-2*sin(tht(n));
    C=cos(tht(n))*(1+k2)+k3+k1;
    stht3=(-B+sqrt(B^2-4*A*C))/(2*A);
    tht3(n)=asin(stht3);
    tht2(n)=acos((-x+a4*cos(tht3(n))-a3*cos(tht(n)))/a2);
    S(n)=AF*sin(tht3(n));
    n=n+1;
    theta=theta+1;
end
theta=0:+1:360;
figure
plot3(theta,real(S),imag(S))
grid minor
title('S grap.')
xlabel('Q (deg)')
ylabel('S')

n=1;
W=86*9.81;
theta=220;
while((theta>=220)&&(theta<=270))
    F_cd(n)=a4*AF*cos(tht3(n));
    T(n)=DC*sin(tht2(n)-tht(n))-(DC*cos(tht2(n))*sin(tht3(n)));
    F_E(n)=T(n)/(AB*cos(theta*pi/180));
    n=n+1;
    theta=theta+1;
end
theta=220:+1:270;
figure
plot(theta,T)
grid minor
title('Torque B Grap.')
xlabel('Q(deg)')
ylabel('Torque')

figure 
plot(theta,F_E)
grid minor 
title('Force A Grap')
xlabel('Q(deg)')
ylabel('Force_A')

Answer 1

[Kevin Holly]

AB=200;
BC=480;
CD=480;
DQ=450;
AQ=480;
FB=100;
DE=600;
AF=300;
ED=600;
DC=CD;
x=AQ;
y=DQ;
a2=CD;
a3=BC;
a4=AB;
a1=-x-y;
k1=a1/a2;
k2=a1/a4;
k3=(a1^2+a2^2-a3^2+a4)/((2*a4^2)*a2);
 
n=1;
theta=220;
while ((theta>=220)&&(theta<=270))
    tht(n)=(theta+210)*(pi/180);
    K=(-a3^2+a1^2+a4^2+a2^2);
    X1=k1*cos(tht(n));
    Y1=k2*cos(tht(n));
    A=cos(tht(n))*(1-k2)+k3-k1;
    B=-2*sin(tht(n));
    C=cos(tht(n))*(1+k2)+k3+k1;
    stht3=(-B+sqrt(B^2-4*A*C))/(2*A);
    tht3(n)=asin(stht3);
    tht2(n)=acos((-x+a4*cos(tht3(n))-a3*cos(tht(n)))/a2);
    S(n)=AF*sin(tht3(n));
    n=n+1;
    theta=theta+1;
end

theta=0:360/(length(real(S))-1):360; % The size of this before was 361 elements. It needed to be 51 elements long.
figure
plot3(theta,real(S),imag(S))
grid minor
title('S grap.')
xlabel('Q (deg)')
ylabel('S')

 
n=1;
W=86*9.81;
theta=220;
while((theta>=220)&&(theta<=270))
    F_cd(n)=a4*AF*cos(tht3(n));
    T(n)=DC*sin(tht2(n)-tht(n))-(DC*cos(tht2(n))*sin(tht3(n)));
    F_E(n)=T(n)/(AB*cos(theta*pi/180));
    n=n+1;
    theta=theta+1;
end
theta=220:+1:270;
figure
plot(theta,T)

Warning: Imaginary parts of complex X and/or Y arguments ignored.

grid minor
title('Torque B Grap.')
xlabel('Q(deg)')
ylabel('Torque')

 
figure 
plot(theta,F_E)

Warning: Imaginary parts of complex X and/or Y arguments ignored.

grid minor 
title('Force A Grap')
xlabel('Q(deg)')
ylabel('Force_A')