amep.utils.in_circle

amep.utils.in_circle(coords: ndarray, radius: float, center: ndarray = array([0, 0, 0]), values: ndarray | None = None, reverse: bool = False, indices: bool = False) → ndarray | tuple[ndarray, ndarray]

Returns the coordinates/values for only particles inside or outside a circular/spherical region of a given radius and centered around a given center position.

Parameters:

• coords (np.ndarray) – Particle coordinates.

• radius (float) – Radius of the spherical/circular region.

• center (np.ndarray, optional) – Center of the region. The default is np.array([0,0,0]).

• values (np.ndarray, optional) – Per-particle values/vectors to return. The default is None.

• reverse (bool) – If True, particle values for particles outside the region are returned. The default is False.

• indices (bool) – If True, particle indices are also returned. The default is False.

Returns:

• values (np.ndarray) – Values for particles in or outside the region.

• ind (np.ndarray) – Particle indices.

Examples

>>> import amep
>>> traj = amep.load.traj("../examples/data/lammps.h5amep")
>>> frame = traj[-1]
>>> center = frame.box.mean(axis=1)
>>> R = 25
>>> inside, idxin = amep.utils.in_circle(
...     frame.coords(), R, indices=True, center=center
... )
>>> outside, idxout = amep.utils.in_circle(
...     frame.coords(), R, reverse=True,
...     indices=True, center=center
... )
>>> fig, axs = amep.plot.new(figsize=(3,3))
>>> amep.plot.particles(
...     axs, inside, frame.box, frame.radius()[idxin],
...     set_ax_limits = False, color='orange'
... )
>>> amep.plot.particles(
...     axs, outside, frame.box, frame.radius()[idxout],
...     set_ax_limits = False
... )
>>> amep.plot.box(axs, frame.box)
>>> angle = np.linspace(0, 2*np.pi, 150)
>>> x = R*np.cos(angle) + center[0]
>>> y = R*np.sin(angle) + center[1]
>>> axs.plot(x, y, c='k', lw=2, marker='')
>>> axs.set_xlabel(r'$x$')
>>> axs.set_ylabel(r'$y$')
>>> fig.savefig('./figures/utils/utils-in_circle.png')
>>>