def _append_array_types(self, array_types):
'''
append to self.array_types the input array_types.
:param array_types: set of array_types to be appended
:type array_types: set()
The set contains either a name as a string, say: 'rise_vel'
In this case, get the ArrayType from gnome.array_types.rise_vel
Set elements could also be tuples, say: ('rise_vel': ArrayType())
In this case the user name of the data_array and its array_type is
specified by the tuple so append it.
.. note:: If a tuple: ('name', ArrayType()), is given and an ArrayType
with that name already exists in self._array_types, then it is
overwritten.
'''
for array in array_types:
if isinstance(array, basestring):
# allow user to override an array_type that might already exist
# in self._array_types
try:
array = getattr(gat, array)
except AttributeError:
msg = ("Skipping {0} - not found in gnome.array_types;"
" and ArrayType is not provided.").format(array)
self.logger.error(msg)
raise GnomeRuntimeError(msg)
# must be an ArrayType of an object
self._array_types[array.name] = array
def _set_init_relative_buoyancy(self, substance):
'''
set the initial relative buoyancy of oil wrt water
use temperature of water to get oil density
if relative_buoyancy < 0 raises a GnomeRuntimeError - particles will
sink.
'''
rho_h2o = self.water.get('density')
rho_oil = substance.density_at_temp(self.water.get('temperature'))
# maybe weathering_data should catch error below?
# todo: write and raise appropriate exception
if np.any(rho_h2o < rho_oil):
msg = ("Found particles with relative_buoyancy < 0. "
"Oil is a sinker")
raise GnomeRuntimeError(msg)
self._init_relative_buoyancy = (rho_h2o - rho_oil) / rho_h2o