The function asymp() corresponds to bode(), but it also plots asymptotes for the magnitude and phase graphs. Phase asymptotes are only horizontal and vertical.
asymp() only accepts SISO transfer functions.
If the transfer function also has a time delay, the time delay is ignored
for the phase asymptotes.
asymp() may be called in two ways only, asymp(h), or asymp(h,wmin,wmax).