def test_constraint_analyser(self):
a = Parameter(1)
b = Parameter(2, constraint=a)
c = Parameter(2.)
d = Parameter(3, constraint=np.cos(b + np.sin(a) + 2 * (a + b + c)))
val = d.value
tree = constraint_tree(d.constraint)
new_constraint = build_constraint_from_tree(tree)
assert_allclose(new_constraint.value, val)
a.value = 10
assert_allclose(new_constraint.value, d.value)
# inject constraint into parameter
e = Parameter(1)
e.constraint = new_constraint
a.value = 11
assert_allclose(e.value, d.value)
# check that it's possible to build a constraint tree from a single
# param
tree = constraint_tree(b.constraint)
new_constraint = build_constraint_from_tree(tree)
e = Parameter(1)
e.constraint = new_constraint
a.value = 0.1234
assert_allclose(e.value, a.value)
# check that it's possible to build a constraint tree from a single
# param
e = Parameter(1)
e.constraint = 2
assert_allclose(e.value, 2)
def test_parameter(self):
# simple test of constraint
x = Parameter(5.0)
y = Parameter(1.0)
y.constraint = x
assert x in y.dependencies()
y.constraint = x * 2.0
assert_equal(y.value, x.value * 2.0)
# parameter should be in y's dependencies
assert x in y._deps
assert x in y.dependencies()
# if you've constrained a parameter it shouldn't be varying
assert_(y.vary is False)
# you can't set a constraint on a parameter with an expression that
# already involves the parameter
from pytest import raises
with raises(ValueError):
x.constraint = y
# try a negative value
x.value = -1.0
assert_equal(y.value, -2.0)
# nested constraints
z = Parameter(1.0)
z.constraint = x + y
assert_equal(z.value, -3)
# check that nested circular constraints aren't allowed
with raises(ValueError):
x.constraint = z
# z = x + y --> z = x + 2*x
# therefore y shouldn't be in z's dependencies, but x should be.
assert x in z.dependencies()
assert y not in z.dependencies()
# absolute value constraint
y.constraint = abs(x)
assert_equal(y.value, 1)
# sin constraint
y.constraint = np.sin(x) + 2.0
assert_equal(y.value, 2.0 + np.sin(x.value))
x.value = 10
assert_equal(y.value, 2.0 + np.sin(10))
def test_parameter(self):
# simple test of constraint
x = Parameter(5.)
y = Parameter(1.)
y.constraint = x * 2.
assert_equal(y.value, x.value * 2.)
# if you've constrained a parameter it shouldn't be varying
assert_(y.vary is False)
# you can't set a constraint on a parameter with an expression that
# already involves the parameter
from pytest import raises
with raises(ValueError):
x.constraint = y
# try a negative value
x.value = -1.
assert_equal(y.value, -2.)
# nested constraints
z = Parameter(1.)
z.constraint = x + y
assert_equal(z.value, -3)
# check that nested circular constraints aren't allowed
with raises(ValueError):
x.constraint = z
# absolute value constraint
y.constraint = abs(x)
assert_equal(y.value, 1)
# sin constraint
y.constraint = np.sin(x) + 2.
assert_equal(y.value, 2. + np.sin(x.value))
def test_sld(self):
p = SLD(5 + 1j, name="pop")
assert_equal(float(p.real), 5)
assert_equal(float(p.imag), 1)
# test that we can cast to complex
assert_equal(complex(p), 5 + 1j)
p = SLD(5)
assert_equal(float(p.real), 5)
q = Parameter(5)
r = Parameter(1)
p = SLD([q, r])
assert_equal(float(p.real), 5)
assert_equal(float(p.imag), 1)
# use SLD to make a Slab
thickness = Parameter(100)
roughness = Parameter(3.0)
vfsolv = Parameter(0.2)
s = p(thickness, roughness)
assert_equal(s.thick.value, thickness.value)
assert_equal(s.rough.value, roughness.value)
assert_equal(s.vfsolv.value, 0)
s = p(thickness, roughness, vfsolv)
assert_equal(s.thick.value, thickness.value)
assert_equal(s.rough.value, roughness.value)
assert_equal(s.vfsolv.value, vfsolv.value)
# check that we can construct SLDs from a constrained par
deut_par = Parameter(6.36)
h2o_solvent = SLD(-0.56)
ms_val = 0.6 * deut_par + 0.4 * h2o_solvent.real
mixed_solvent = SLD(ms_val)
assert isinstance(mixed_solvent.real, _BinaryOp)
sld = complex(mixed_solvent)
assert_allclose(sld.real, 0.6 * 6.36 + 0.4 * -0.56)
deut_par.value = 5.0
sld = complex(mixed_solvent)
assert_allclose(sld.real, 0.6 * 5.0 + 0.4 * -0.56)
