if isinstance(coordinates, Mapping):
coordinates = coordinates.items()
self = object().__new__(cls)
- self._coordinates = OrderedDict()
- for symbol, coordinate in sorted(coordinates,
- key=lambda item: item[0].sortkey()):
+ self._coordinates = []
+ for symbol, coordinate in coordinates:
if not isinstance(symbol, Symbol):
raise TypeError('symbols must be Symbol instances')
if not isinstance(coordinate, numbers.Real):
raise TypeError('coordinates must be real numbers')
- self._coordinates[symbol] = coordinate
+ self._coordinates.append((symbol, coordinate))
+ self._coordinates.sort(key=lambda item: item[0].sortkey())
+ self._coordinates = OrderedDict(self._coordinates)
return self
@property
"""
return any(self._coordinates.values())
+ def __eq__(self, other):
+ """
+ Return True if two coordinate systems are equal.
+ """
+ if isinstance(other, self.__class__):
+ return self._coordinates == other._coordinates
+ return NotImplemented
+
def __hash__(self):
return hash(tuple(self.coordinates()))
"""
Translate the point by a Vector object and return the resulting point.
"""
- if not isinstance(other, Vector):
- return NotImplemented
- coordinates = self._map2(other, operator.add)
- return Point(coordinates)
+ if isinstance(other, Vector):
+ coordinates = self._map2(other, operator.add)
+ return Point(coordinates)
+ return NotImplemented
def __sub__(self, other):
"""
- If other is a point, substract a point from another and returns the
- resulting vector. If other is a vector, translate the point by the
- opposite vector and returns the resulting point.
+ If other is a point, substract it from self and return the resulting
+ vector. If other is a vector, translate the point by the opposite vector
+ and returns the resulting point.
"""
coordinates = []
if isinstance(other, Point):
elif isinstance(other, Vector):
coordinates = self._map2(other, operator.sub)
return Point(coordinates)
- else:
- return NotImplemented
-
- def __eq__(self, other):
- """
- Test whether two points are equal.
- """
- return isinstance(other, Point) and \
- self._coordinates == other._coordinates
+ return NotImplemented
def aspolyhedron(self):
from .polyhedra import Polyhedron
def __new__(cls, initial, terminal=None):
"""
Create a vector from a dictionary or a sequence that maps the symbols to
- their coordinates, or as the difference between two points.
+ their coordinates, or as the displacement between two points.
"""
if not isinstance(initial, Point):
initial = Point(initial)
"""
Multiplies a Vector by a scalar value.
"""
- if not isinstance(other, numbers.Real):
- return NotImplemented
- coordinates = self._map(lambda coordinate: other * coordinate)
- return Vector(coordinates)
+ if isinstance(other, numbers.Real):
+ coordinates = self._map(lambda coordinate: other * coordinate)
+ return Vector(coordinates)
+ return NotImplemented
__rmul__ = __mul__
Divide the vector by the specified scalar and returns the result as a
vector.
"""
- if not isinstance(other, numbers.Real):
- return NotImplemented
- coordinates = self._map(lambda coordinate: coordinate / other)
- return Vector(coordinates)
-
- def __eq__(self, other):
- """
- Test whether two vectors are equal.
- """
- return isinstance(other, Vector) and \
- self._coordinates == other._coordinates
+ if isinstance(other, numbers.Real):
+ coordinates = self._map(lambda coordinate: coordinate / other)
+ return Vector(coordinates)
+ return NotImplemented
def angle(self, other):
"""
def cross(self, other):
"""
Compute the cross product of two 3D vectors. If either one of the
- vectors is not tridimensional, a ValueError exception is raised.
+ vectors is not three-dimensional, a ValueError exception is raised.
"""
if not isinstance(other, Vector):
raise TypeError('other must be a Vector instance')
return result
def __hash__(self):
- return hash(tuple(self.coordinates()))
+ return super().__hash__()
def norm(self):
"""