Class Volume

python/simulation.py:402–507

Many Meep functions require you to specify a volume in space, corresponding to the C++ type `meep::volume`. This class creates such a volume object, given the `center` and `size` properties (just like e.g. a `Block` object). If the `size` is not specified, it defaults to `(0,0,0)`,

class Volume:
    """
    Many Meep functions require you to specify a volume in space, corresponding to the C++
    type `meep::volume`. This class creates such a volume object, given the `center` and
    `size` properties (just like e.g. a `Block` object). If the `size` is not specified,
    it defaults to `(0,0,0)`, i.e. a single point. Any method that accepts such a volume
    also accepts `center` and `size` keyword arguments. If these are specified instead of
    the volume, the library will construct a volume for you. Alternatively, you can
    specify a list of `Vector3` vertices using the `vertices` parameter. The `center` and
    `size` will automatically be computed from this list.
    """

    def __init__(
        self,
        center: Vector3Type = Vector3(),
        size: Vector3Type = Vector3(),
        dims: int = 2,
        is_cylindrical: bool = False,
        vertices: Optional[List[Vector3Type]] = None,
    ):
        """
        Construct a Volume.
        """
        if not vertices:
            self.center = Vector3(*center)
            self.size = Vector3(*size)
        else:
            vertices = np.array([np.array(i) for i in vertices])
            self.center = Vector3(*np.mean(vertices, axis=0))
            x_list = np.unique(vertices[:, 0])
            y_list = np.unique(vertices[:, 1])
            z_list = np.unique(vertices[:, 2])

            x_size = 0 if x_list.size == 1 else np.abs(np.diff(x_list)[0])
            y_size = 0 if y_list.size == 1 else np.abs(np.diff(y_list)[0])
            z_size = 0 if z_list.size == 1 else np.abs(np.diff(z_list)[0])

            self.size = Vector3(x_size, y_size, z_size)

        self.dims = dims

        v1 = self.center - self.size.scale(0.5)
        v2 = self.center + self.size.scale(0.5)

        vec1 = py_v3_to_vec(self.dims, v1, is_cylindrical)
        vec2 = py_v3_to_vec(self.dims, v2, is_cylindrical)

        self.swigobj = mp.volume(vec1, vec2)

    def get_vertices(self):
        xmin = self.center.x - self.size.x / 2
        xmax = self.center.x + self.size.x / 2
        ymin = self.center.y - self.size.y / 2
        ymax = self.center.y + self.size.y / 2
        zmin = self.center.z - self.size.z / 2
        zmax = self.center.z + self.size.z / 2

        # Iterate over and remove duplicates for collapsed dimensions (i.e. min=max))