With as a pole and as a zero of the transfer function. Poles and zeros are always real or complex conjugate.
The Java applet shows the domain of a system with two poles and two zeros. Poles (×) and zeros (O) can be dragged with the mouse. The amplitude response and the phase response are shown along side. Plot: |H(s)| may takes a while.
The source code (version 96/09/28) and the GPL.
[ www.thole.org | Manfred Thole ]