Fing the Bug
The following MATLAB code cannot plot 13 cycles of a 13Hz sinusoid because this code has too large step function.
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)
To plot 13 cycles of a 13Hz sinusoid, I reduced the value of step function.
Ts=0.07*0.01;