import operator
from abc import ABC, abstractmethod
-from collections import OrderedDict
+from collections import OrderedDict, Mapping
from .linexprs import Symbol
This class represents points in space.
"""
- def __new__(cls, coordinates=None):
- if isinstance(coordinates, dict):
+ def __new__(cls, coordinates):
+ if isinstance(coordinates, Mapping):
coordinates = coordinates.items()
self = object().__new__(cls)
self._coordinates = OrderedDict()
return isinstance(other, Point) and \
self._coordinates == other._coordinates
+ def aspolyhedron(self):
+ from .polyhedra import Polyhedron
+ equalities = []
+ for symbol, coordinate in self.coordinates():
+ equalities.append(symbol - coordinate)
+ return Polyhedron(equalities)
+
class Vector(Coordinates):
"""
self._coordinates = terminal._map2(initial, operator.sub)
return self
- @property
- def symbols(self):
- return tuple(self._coordinates)
-
- @property
- def dimension(self):
- return len(self.symbols)
-
- def coordinates(self):
- yield from self._coordinates.items()
-
- def coordinate(self, symbol):
- if not isinstance(symbol, Symbol):
- raise TypeError('symbol must be a Symbol instance')
- return self._coordinates[symbol]
-
- __getitem__ = coordinate
-
def isnull(self):
return not bool(self)
- def __bool__(self):
- return any(self._coordinates.values())
-
def __add__(self, other):
if isinstance(other, (Point, Vector)):
coordinates = self._map2(other, operator.add)
coordinates = self._map2(other, operator.sub)
return other.__class__(coordinates)
return NotImplemented
-
- def __repr__(self):
- string = ', '.join(['{!r}: {!r}'.format(symbol, coordinate)
- for symbol, coordinate in self.coordinates()])
- return '{}({{{}}})'.format(self.__class__.__name__, string)