"""Support for 3-partner connections between gmso.core.Atoms."""
from typing import Callable, ClassVar, Optional, Tuple
from pydantic import Field
from gmso.abc.abstract_connection import Connection
from gmso.core.angle_type import AngleType
from gmso.core.atom import Atom
[docs]class Angle(Connection):
__base_doc__ = """A 3-partner connection between Atoms.
This is a subclass of the gmso.Connection superclass.
This class has strictly 3 members in its connection members.
The connection_type in this class corresponds to gmso.AngleType.
Notes
-----
Inherits some methods from Connection:
__eq__, __repr__, _validate methods
Additional _validate methods are presented
"""
__members_creator__: ClassVar[Callable] = Atom.parse_obj
connection_members_: Tuple[Atom, Atom, Atom] = Field(
..., description="The 3 atoms involved in the angle."
)
angle_type_: Optional[AngleType] = Field(
default=None, description="AngleType of this angle."
)
@property
def angle_type(self):
"""Return the angle type if the angle is parametrized."""
return self.__dict__.get("angle_type_")
@property
def connection_type(self):
"""Return the angle type if the angle is parametrized."""
return self.__dict__.get("angle_type_")
[docs] def equivalent_members(self):
"""Return a set of the equivalent connection member tuples.
Returns
-------
frozenset
A unique set of tuples of equivalent connection members
Notes
-----
For an angle:
i, j, k == k, j, i
where i, j and k are the connection members.
"""
return frozenset(
[self.connection_members, tuple(reversed(self.connection_members))]
)
def _equivalent_members_hash(self):
"""Return a unique hash representing the connection.
Returns
-------
int
A unique hash to represent the connection members
Notes
-----
For an angle:
i, j, k == k, j, i
where i, j, and k are the connection members.
Here, j is fixed and i and k are replaceable.
"""
return hash(
tuple(
[
self.connection_members[1],
frozenset(
[self.connection_members[0], self.connection_members[2]]
),
]
)
)
def __setattr__(self, key, value):
"""Set the attributes of the angle."""
if key == "connection_type":
super(Angle, self).__setattr__("angle_type", value)
else:
super(Angle, self).__setattr__(key, value)
[docs] class Config:
"""Support pydantic configuration for attributes and behavior."""
fields = {
"connection_members_": "connection_members",
"angle_type_": "angle_type",
}
alias_to_fields = {
"connection_members": "connection_members_",
"angle_type": "angle_type_",
}