why is my graph not showing any lines

t=1;
R=1;
Ro=10;
a1=0.25;
a2=0.5;
a3=0.75;
a4=1;
w=0.001:1:1000;
Q=w.*t;
y=log10(w);
c1=cos(a1.*0.5*pi);
c2=cos(a2.*0.5*pi);
c3=cos(a3.*0.5*pi);
c4=cos(a4.*0.5*pi);
W1=Q.^(a1);
W21=Q.^(2.*a1);
W2=Q.^(a2);
W22=Q.^(2.*a2);
W3=Q.^(a3);
W23=Q.^(2.*a3);
W4=Q.^(a4);
W24=Q.^(2.*a4);
ModZ1=((((R.^2).*W21)+(2.*R.*Ro.*c1.*W1)+(Ro.^2))/(1+(2.*c1.*W1)+W21));
ModZ2=((((R.^2).*W22)+(2.*R.*Ro.*c2.*W1)+(Ro.^2))/(1+(2.*c2.*W2)+W22));
ModZ3=((((R.^2).*W23)+(2.*R.*Ro.*c3.*W1)+(Ro.^2))/(1+(2.*c3.*W3)+W23));
ModZ4=((((R.^2).*W24)+(2.*R.*Ro.*c4.*W1)+(Ro.^2))/(1+(2.*c4.*W4)+W24));
plot(y,ModZ1)
hold on
plot(y,ModZ2)
plot(y,ModZ3)
plot(y,ModZ4)

Answer 1

[Image Analyst]

I thin you forgot to use dot slash instead of slash when you were dividing. Try this:

t=1;
R=1;
Ro=10;
a1=0.25;
a2=0.5;
a3=0.75;
a4=1;
w=0.001:1:1000;
Q=w.*t;
y=log10(w);
c1=cos(a1.*0.5*pi);
c2=cos(a2.*0.5*pi);
c3=cos(a3.*0.5*pi);
c4=cos(a4.*0.5*pi);
W1=Q.^(a1);
W21=Q.^(2.*a1);
W2=Q.^(a2);
W22=Q.^(2.*a2);
W3=Q.^(a3);
W23=Q.^(2.*a3);
W4=Q.^(a4);
W24=Q.^(2.*a4);
ModZ1=((((R.^2).*W21)+(2.*R.*Ro.*c1.*W1)+(Ro.^2)) ./ (1+(2.*c1.*W1)+W21));
ModZ2=((((R.^2).*W22)+(2.*R.*Ro.*c2.*W1)+(Ro.^2)) ./ (1+(2.*c2.*W2)+W22));
ModZ3=((((R.^2).*W23)+(2.*R.*Ro.*c3.*W1)+(Ro.^2)) ./ (1+(2.*c3.*W3)+W23));
ModZ4=((((R.^2).*W24)+(2.*R.*Ro.*c4.*W1)+(Ro.^2)) ./ (1+(2.*c4.*W4)+W24));
plot(y,ModZ1, 'LineWidth', 2)
hold on
plot(y,ModZ2, 'LineWidth', 2)
plot(y,ModZ3, 'LineWidth', 2)
plot(y,ModZ4, 'LineWidth', 2)
grid on;
fprintf('Done!\n');
legend('ModZ1', 'ModZ2', 'ModZ3', 'ModZ4');
xlabel('y', 'FontSize', 15);
ylabel('ModZn', 'FontSize', 15);