Fixing Matlab Code
The code provided:
F0 =13; T0 =1/F0; Ts = 0.07; t = 0:Ts:13*T0; x = real(exp(j*(2*pi*F0*t-pi/2))); plot(t,x)
The problem here is that the code is not sampling fast enough. Increasing the rate at which it samples will provide a higher resolution image. To do this we must change Ts. I chose to change it to .0001.
F0 =13; T0 =1/F0; Ts = 0.0001; t = 0:Ts:13*T0; x = real(exp(j*(2*pi*F0*t-pi/2))); plot(t,x)