Hi,

I have a user defined field with the following definition.

def _epsilon(field, data):
    return (4.0/3.0)*(data['vShock']/data["VelocityMagnitude"])
add_field("epsilon", function=_epsilon, take_log=False, units=r" " ) 

Now I would like take ln(1 + data["epsilon"]). I am trying with the following definition. Is this the correct way of doing this ? 

def _lnepsilon(field, data):
    return 1 + data["epsilon"]
add_field("lnepsilon", function=_lnepsilon, take_log=True, units=r" " ) 

Thank you
--
Reju Sam John