Finding the Bug

The code below is suppose to plot 13 cycles of a sinusoidal wave. However there is a problem with the code. The problem in the following 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)

Is that the sample rate Ts is incorrect. In the example Ts is too large and should be less than 1/26 instead. The current sampling rate causes matlab to take points the signal are at distances between the points greater than the half of the period of the waveform. As a result it does not produce the correct plot.

Alumni Liaison

Ph.D. 2007, working on developing cool imaging technologies for digital cameras, camera phones, and video surveillance cameras.

Buyue Zhang