def test_properties():
"""
Test accessing the various properties of equation objects
"""
tau = 10 * ms
eqs = Equations("""dv/dt = -(v + I)/ tau : volt
I = sin(2 * 22/7. * f * t)* volt : volt
f = freq * Hz: Hz
freq : 1""")
assert (len(eqs.diff_eq_expressions) == 1
and eqs.diff_eq_expressions[0][0] == 'v'
and isinstance(eqs.diff_eq_expressions[0][1], Expression))
assert eqs.diff_eq_names == {'v'}
assert (len(eqs.eq_expressions) == 3
and {name
for name, _ in eqs.eq_expressions} == {'v', 'I', 'f'} and all(
(isinstance(expr, Expression)
for _, expr in eqs.eq_expressions)))
assert len(eqs.eq_names) == 3 and eqs.eq_names == {'v', 'I', 'f'}
assert set(eqs.keys()) == {'v', 'I', 'f', 'freq'}
# test that the equations object is iterable itself
assert all((isinstance(eq, SingleEquation) for eq in eqs.values()))
assert all((isinstance(eq, str) for eq in eqs))
assert (len(eqs.ordered) == 4 and all(
(isinstance(eq, SingleEquation) for eq in eqs.ordered))
and [eq.varname for eq in eqs.ordered] == ['f', 'I', 'v', 'freq'])
assert [eq.unit for eq in eqs.ordered] == [Hz, volt, volt, 1]
assert eqs.names == {'v', 'I', 'f', 'freq'}
assert eqs.parameter_names == {'freq'}
assert eqs.subexpr_names == {'I', 'f'}
dimensions = eqs.dimensions
assert set(dimensions.keys()) == {'v', 'I', 'f', 'freq'}
assert dimensions['v'] is volt.dim
assert dimensions['I'] is volt.dim
assert dimensions['f'] is Hz.dim
assert dimensions['freq'] is DIMENSIONLESS
assert eqs.names == set(eqs.dimensions.keys())
assert eqs.identifiers == {'tau', 'volt', 'Hz', 'sin', 't'}
# stochastic equations
assert len(eqs.stochastic_variables) == 0
assert eqs.stochastic_type is None
eqs = Equations("""dv/dt = -v / tau + 0.1*second**-.5*xi : 1""")
assert eqs.stochastic_variables == {'xi'}
assert eqs.stochastic_type == 'additive'
eqs = Equations(
"""dv/dt = -v / tau + 0.1*second**-.5*xi_1 + 0.1*second**-.5*xi_2: 1"""
)
assert eqs.stochastic_variables == {'xi_1', 'xi_2'}
assert eqs.stochastic_type == 'additive'
eqs = Equations("""dv/dt = -v / tau + 0.1*second**-1.5*xi*t : 1""")
assert eqs.stochastic_type == 'multiplicative'
eqs = Equations("""dv/dt = -v / tau + 0.1*second**-1.5*xi*v : 1""")
assert eqs.stochastic_type == 'multiplicative'
def test_str_repr():
"""
Test the string representation (only that it does not throw errors).
"""
tau = 10 * ms
eqs = Equations("""dv/dt = -(v + I)/ tau : volt (unless refractory)
I = sin(2 * 22/7. * f * t)* volt : volt
f : Hz""")
assert len(str(eqs)) > 0
assert len(repr(eqs)) > 0
# Test str and repr of SingleEquations explicitly (might already have been
# called by Equations
for eq in eqs.values():
assert (len(str(eq))) > 0
assert (len(repr(eq))) > 0