Supplied code:
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 with the code is that Ts is too large. If Ts were to be 0.007 or even better, 0.0007, then there are 13 cycles displayed.
