.. py:function:: potential_temperature(t, p)
Computes the potential temperature for a given temperature (``t``) and pressure (``p``).
:param t: temperature (K)
:type t: number
:param p: pressure (Pa)
:type p: number
:rtype: number or None
The result is the potential temperature in K units. On error None is returned.
.. mv-minigallery:: potential_temperature