def test_set_nb_func_bad(self):
# Try changing the nonbonded function, keep the parameters,
# but the nb function uses different symbols
first_type = AtomType(expression='r*sigma*epsilon',
parameters={'sigma': 1*u.m, 'epsilon': 100*u.m},
independent_variables='r')
with pytest.raises(ValueError):
first_type.set_expression(expression='a + b')
def test_set_nb_func_params_both_incorrect(self):
# Try incorrectly changing both the nb function and the parameters
first_type = AtomType(expression='r*sigma*epsilon',
parameters={'sigma': 1*u.m, 'epsilon': 10*u.J},
independent_variables='r')
with pytest.raises(ValueError):
first_type.set_expression(expression='a*x+b',
parameters={'c': 100*u.year, 'd': 42*u.newton},
independent_variables='x')
def test_set_nb_func(self, charge):
# Try changing the nonbonded function, but keep the parameters
first_type = AtomType(name='mytype', charge=charge,
parameters={'sigma': 1*u.m, 'epsilon': 10*u.m},
independent_variables='r')
first_type.set_expression(expression='r * (sigma + epsilon)')
correct_expr = sympy.sympify('r * (sigma + epsilon)')
assert first_type.expression == correct_expr
assert first_type.parameters == {'sigma': 1*u.m, 'epsilon': 10*u.m}
def test_set_nb_func_params_bad(self):
# Try changing the parameters, keep the function,
# but the new parameters use different symbols
first_type = AtomType(expression='r*sigma*epsilon',
parameters={'sigma': 1*u.m, 'epsilon': 10*u.J},
independent_variables={'r'})
with pytest.raises(ValueError):
first_type.set_expression(parameters={'a': 1*u.g, 'b': 10*u.m})
def test_set_nb_func_params_both_correct(self):
# Try correctly changing both the nb function and parameters
first_type = AtomType(expression='r*sigma*epsilon',
parameters={'sigma': 1*u.m, 'epsilon': 10*u.J},
independent_variables='r')
first_type.set_expression(expression='a+b*x', parameters={'a': 100*u.m, 'b': 42*u.J}, independent_variables='x')
correct_expr = sympy.sympify('a+b*x')
correct_params = {'a': 100*u.m, 'b': 42*u.J}
assert first_type.expression == correct_expr
assert first_type.parameters == correct_params
def test_set_nb_func_params_partial(self):
# Try changing the parameters, keep the function,
# but change only one symbol
first_type = AtomType(expression='r*sigma*epsilon',
parameters={'sigma': 1*u.m, 'epsilon': 10*u.J},
independent_variables={'r'})
first_type.set_expression(parameters={'sigma': 42*u.m})
correct_expr = sympy.sympify('r*sigma*epsilon')
assert first_type.parameters == {'sigma': 42*u.m, 'epsilon': 10*u.J}
assert first_type.expression == correct_expr
def test_set_nb_func_params(self, charge):
# Try changing the nb parameters, but keeping the function
first_type = AtomType(name='mytype', charge=charge,
expression='r * sigma * epsilon',
parameters={'sigma': 1*u.m, 'epsilon': 10*u.m},
independent_variables='r')
first_type.set_expression(parameters={'sigma': 42*u.m, 'epsilon': 24*u.m})
correct_expr = sympy.sympify('r * sigma * epsilon')
assert first_type.expression == correct_expr
assert first_type.parameters == {'sigma': 42, 'epsilon': 24}
def test_set_nb_func_params_bad(self):
# Try changing the parameters, keep the function,
# but the new parameters use different symbols
first_type = AtomType(
expression="r*sigma*epsilon",
parameters={"sigma": 1 * u.m, "epsilon": 10 * u.J},
independent_variables={"r"},
)
with pytest.raises(ValueError):
first_type.set_expression(parameters={"a": 1 * u.g, "b": 10 * u.m})
def test_set_nb_func(self, charge):
# Try changing the nonbonded function, but keep the parameters
first_type = AtomType(
name="mytype",
charge=charge,
parameters={"sigma": 1 * u.m, "epsilon": 10 * u.m},
independent_variables="r",
)
first_type.set_expression(expression="r * (sigma + epsilon)")
correct_expr = sympy.sympify("r * (sigma + epsilon)")
assert first_type.expression == correct_expr
assert first_type.parameters == {"sigma": 1 * u.m, "epsilon": 10 * u.m}
def test_set_nb_func_params_both_incorrect(self):
# Try incorrectly changing both the nb function and the parameters
first_type = AtomType(
expression="r*sigma*epsilon",
parameters={"sigma": 1 * u.m, "epsilon": 10 * u.J},
independent_variables="r",
)
with pytest.raises(ValueError):
first_type.set_expression(
expression="a*x+b",
parameters={"c": 100 * u.year, "d": 42 * u.newton},
independent_variables="x",
)
def test_set_nb_func_params(self, charge):
# Try changing the nb parameters, but keeping the function
first_type = AtomType(
name="mytype",
charge=charge,
expression="r * sigma * epsilon",
parameters={"sigma": 1 * u.m, "epsilon": 10 * u.m},
independent_variables="r",
)
first_type.set_expression(
parameters={"sigma": 42 * u.m, "epsilon": 24 * u.m}
)
correct_expr = sympy.sympify("r * sigma * epsilon")
assert first_type.expression == correct_expr
assert first_type.parameters == {"sigma": 42, "epsilon": 24}
def test_set_nb_func_params_both_correct(self):
# Try correctly changing both the nb function and parameters
first_type = AtomType(
expression="r*sigma*epsilon",
parameters={"sigma": 1 * u.m, "epsilon": 10 * u.J},
independent_variables="r",
)
first_type.set_expression(
expression="a+b*x",
parameters={"a": 100 * u.m, "b": 42 * u.J},
independent_variables="x",
)
correct_expr = sympy.sympify("a+b*x")
correct_params = {"a": 100 * u.m, "b": 42 * u.J}
assert first_type.expression == correct_expr
assert first_type.parameters == correct_params
