def add_alias_field(self, alias, field, units=None,
force_add=True):
r"""
Add a field as an alias to another field.
Parameters
----------
alias : string
Alias name.
field : string
The field to be aliased.
units : optional, string
Units in which the field will be returned.
force_add : optional, bool
If True, add field even if it already exists and warn the
user and raise an exception if dependencies do not exist.
If False, silently do nothing in both instances.
Default: True.
Examples
--------
>>> import ytree
>>> a = ytree.load("tree_0_0_0.dat")
>>> # "Mvir" exists on disk
>>> a.add_alias_field("mass", "Mvir", units="Msun")
>>> print (a["mass"])
"""
if alias in self.field_info:
if force_add:
ftype = self.field_info[alias].get("type", "on-disk")
if ftype in ["alias", "derived"]:
fl = self.derived_field_list
else:
fl = self.field_list
mylog.warn(
("Overriding field \"%s\" that already " +
"exists as %s field.") % (alias, ftype))
fl.pop(fl.index(alias))
else:
return
if field not in self.field_info:
if force_add:
raise ArborFieldDependencyNotFound(
field, alias, arbor=self)
else:
return
if units is None:
units = self.field_info[field].get("units")
self.derived_field_list.append(alias)
self.field_info[alias] = \
{"type": "alias", "units": units,
"dependencies": [field]}
if "aliases" not in self.field_info[field]:
self.field_info[field]["aliases"] = []
self.field_info[field]["aliases"].append(alias)
def add_alias_field(self, alias, field, units=None, force_add=True):
"""
Add an alias field.
"""
if alias in self:
if force_add:
ftype = self[alias].get("type", "on-disk")
if ftype in ["alias", "derived"]:
fl = self.arbor.derived_field_list
else:
fl = self.arbor.field_list
mylog.warning(f"Overriding field \"{alias}\" that already "
f"exists as {ftype} field.")
fl.pop(fl.index(alias))
else:
return
if field not in self:
if force_add:
raise ArborFieldDependencyNotFound(field, alias, arbor=self)
else:
return
if units is None:
units = self[field].get("units")
self.arbor.derived_field_list.append(alias)
self[alias] = \
{"type": "alias", "units": units,
"dependencies": [field]}
if "aliases" not in self[field]:
self[field]["aliases"] = []
self[field]["aliases"].append(alias)
def __missing__(self, key):
if key not in self.arbor.field_info:
raise ArborFieldDependencyNotFound(self.name, key, self.arbor)
fi = self.arbor.field_info[key]
units = fi.get("units", "")
if fi.get("vector_field", False):
data = np.ones((1, 3))
else:
data = np.ones(1)
self[key] = self.arbor.arr(data, units)
return self[key]
def __missing__(self, key):
if key not in self.arbor.field_info:
raise ArborFieldDependencyNotFound(self.name, key, self.arbor)
units = self.arbor.field_info[key].get("units", "")
self[key] = self.arbor.arr(np.ones(1), units)
return self[key]
def _validate_key(self, key):
if key not in self.arbor.field_info:
raise ArborFieldDependencyNotFound(self.name, key, self.arbor)