Class Sphere

phi/geom/_sphere.py:41–196

N-dimensional sphere. Defined through center position and radius.

@sliceable(keepdims='vector')
@dataclass(frozen=True, eq=False)
class Sphere(Geometry, metaclass=SphereType):
    """
    N-dimensional sphere.
    Defined through center position and radius.
    """
    
    pos: Tensor
    radius: Tensor
    
    variable_attrs: Tuple[str, ...] = ('pos', 'radius')
    
    def __post_init__(self):
        assert 'vector' in self.pos.shape
        assert 'vector' not in self.radius.shape, f"Sphere radius must not vary along vector but got {self.radius}"

    @cached_property
    def shape(self):
        return self.pos.shape & self.radius.shape

    @property
    def center(self):
        return self.pos

    @cached_property
    def volume(self) -> math.Tensor:
        return Sphere.volume_from_radius(self.radius, self.spatial_rank)

    @staticmethod
    def volume_from_radius(radius: Union[float, Tensor], spatial_rank: int):
        if spatial_rank == 1:
            return 2 * radius
        elif spatial_rank == 2:
            return PI * radius ** 2
        elif spatial_rank == 3:
            return 4/3 * PI * radius ** 3
        else:
            raise NotImplementedError(f"spatial_rank>3 not supported, got {spatial_rank}")
            # n = self.spatial_rank
            # return math.pi ** (n // 2) / math.faculty(math.ceil(n / 2)) * self.radius ** n

    @staticmethod
    def radius_from_volume(volume: Union[float, Tensor], spatial_rank: int):
        if spatial_rank == 1:
            return volume / 2
        elif spatial_rank == 2:
            return math.sqrt(volume / PI)
        elif spatial_rank == 3:
            return (.75 / PI * volume) ** (1/3)
        else:
            raise NotImplementedError(f"spatial_rank>3 not supported, got {spatial_rank}")

    @staticmethod
    def area_from_radius(radius: Union[float, Tensor], spatial_rank: int):
        if spatial_rank == 1:
            return 0
        elif spatial_rank == 2:
            return 2*PI * radius
        elif spatial_rank == 3: