# Determine phase response from pole-zero plot

I know how to determine the frequency response from the pole-zero diagram given the following formula:

$$\left | H(f) \right | = \frac{\prod \left | (e^{j2\pi f} - a_{i})\right |}{\prod \left | (e^{j2\pi f} - b_{j})\right |}$$

where f is a normalized frequency varying from 0 to $$\frac{1}{2}$$ and a and b are values of zeros and poles respectively.

It is easy with this to draw up the frequency response but how can you determine the phase response (linear, minimal, etc.) with a given equation (and therefore pole-zero diagram) ?