MATLAB: With even numbers the sin looks completly different that with odd number

cosModulationplotsin

Hello!! I am plotting an easy sin function but I dont understand why when the variable delta is 0.2 0.4 0.6 and so on I get a perfect sin, but on the other hand when I plot it with delta 0.1 0.3 0.5 I get a diffrent plot. I think has to be something with the modulation. Here is goes the code
f=linspace(0.1,10e6);
delta=0.2;
y=sin(pi*f.*delta);
plot(f,y)
Thanks a lot Nicolas

Best Answer

  • Nicolas, the problem is with your use of linspace(). The way you are using it you are generating a vector with 100 points equally spaced between 0.1 and 10 million, so the spacing between each of your time points is on the order of 100,000!
    t = linspace(0,40,4000);
    delta1 = 0.1;
    delta2 = 0.2;
    y1 = sin(pi*delta1*t);
    y2 = sin(pi*delta2*t);
    plot(t,y1,'r');
    hold on;
    plot(t,y2,'b');