def test_micro_slab(self):
# test micro-slab representation by calculating reflectivity from a
# structure with default interfacial profiles for all the components.
# Then specify an Erf interface for the slab and check that the
# reflectivity signal is the same.
sio2 = self.sio2(100, 5)
d2o = self.d2o(0, 4)
s = self.air | sio2 | d2o
s.contract = -1
q = np.linspace(0.01, 0.5, 101)
reflectivity = s.reflectivity(q)
sio2.interfaces = Erf()
d2o.interfaces = Erf()
micro_slab_reflectivity = s.reflectivity(q)
# Should be within 1%
# How close the micro-slicing is to the Nevot-Croce is going to
# depend on the exact system you look at, and what slice thickness
# is used.
assert_allclose(micro_slab_reflectivity, reflectivity, rtol=0.01)
# test out user defined roughness type
class Cauchy(Interface):
def __call__(self, x, loc=0, scale=1):
return cauchy.cdf(x, loc=loc, scale=scale)
c = Cauchy()
sio2.interfaces = c
s.reflectivity(q)
# imaginary part of micro slab should be calculated in same way as
# real part
fronting = SLD(1 + 1j)
layer = SLD(4 + 4j)
backing = SLD(6 + 6j)
s = fronting | layer(100, 4) | backing(0, 4)
s[1].interfaces = Erf()
s[-1].interfaces = Erf()
slabs = s.slabs()
assert_almost_equal(slabs[:, 1], slabs[:, 2])
def test_interface(self):
# can we set the interface property correctly
c = self.sio2(10, 3)
assert c.interfaces is None
c.interfaces = Erf()
assert isinstance(c.interfaces, Erf)
c.interfaces = [Erf()]
assert isinstance(c.interfaces, Erf)
c.interfaces = None
assert c.interfaces is None
import pytest
with pytest.raises(ValueError):
c.interfaces = [1]
# because len(c.slabs()) = 1
with pytest.raises(ValueError):
c.interfaces = [Erf(), Erf()]
def test_erf(self):
i = Erf()
profile = i(self.x, scale=1.1, loc=-1.)
assert_equal(profile, norm.cdf(self.x, scale=1.1, loc=-1.))