def test_volume_conversion():
"""tests conversion of volume and radius of droplet"""
for dim in [1, 2, 3]:
radius = 1 + random.random()
volume = spherical.volume_from_radius(radius, dim=dim)
radius2 = spherical.radius_from_volume(volume, dim=dim)
assert radius2 == pytest.approx(radius)
def test_surface():
"""test whether the surface is calculated correctly"""
for dim in [1, 2, 3]:
radius = 1 + random.random()
eps = 1e-10
vol1 = spherical.volume_from_radius(radius + eps, dim=dim)
vol0 = spherical.volume_from_radius(radius, dim=dim)
surface_approx = (vol1 - vol0) / eps
surface = spherical.surface_from_radius(radius, dim=dim)
assert surface == pytest.approx(surface_approx, rel=1e-3)
r2s = spherical.make_surface_from_radius_compiled(dim)
assert surface == pytest.approx(r2s(radius))
if dim == 1:
with pytest.raises(RuntimeError):
spherical.radius_from_surface(surface, dim=dim)
else:
assert spherical.radius_from_surface(
surface, dim=dim) == pytest.approx(radius)
def volume(self) -> float:
"""float: volume of the droplet"""
return spherical.volume_from_radius(self.radius, self.dim)
def volume_approx(self) -> float:
"""float: approximate volume to linear order in the perturbation"""
volume = spherical.volume_from_radius(self.radius, 3)
if len(self.amplitudes) > 0:
volume += self.amplitudes[0] * 2 * np.sqrt(np.pi) * self.radius**2
return volume