Poles and zeros are treated the same with regards creation, so we will look here at poles only. The meaning of a pole and a zero only becomes important when creating a pole/zero model.
Poles are specified by in the LTPDA Toolbox by a frequency, f, and (optionally) a quality factor, Q.
The following code fragment creates a real pole at 1Hz:
>> p1 = pole(1) ---- pole 1 ---- real pole: 1 Hz ----------------
>> p1 = pole(10, 4) ---- pole 1 ---- complex pole: 10 Hz, Q=4 [-0.0019894+0.015791i] ----------------