Related distribution functions may allow bulk fluid flow, in which case the velocity origin is shifted, so that the exponent's numerator is m ( ( v x − − u x ) 2 + ( v y − − u y ) 2 + ( v z − − u z ) 2 ) , where ( u x , u y , u z ) is the bulk velocity of the fluid. Distribution functions may also feature non-isotropic temperatures, in which each term in the exponent is divided by a different temperature.