def test_fit_to_data(self):
"""
Test the Wilhoit.fit_to_data() method.
"""
h298 = self.wilhoit.get_enthalpy(298)
s298 = self.wilhoit.get_entropy(298)
Tdata = np.array([300., 400., 500., 600., 800., 1000., 1500.])
cp_data = np.zeros_like(Tdata)
for i in range(Tdata.shape[0]):
cp_data[i] = self.wilhoit.get_heat_capacity(Tdata[i])
cp_0 = self.Cp0 * constants.R
cp_inf = self.CpInf * constants.R
# Fit the Wilhoit polynomial to the data
wilhoit = Wilhoit().fit_to_data(Tdata, cp_data, cp_0, cp_inf, h298,
s298)
# Check that the fit reproduces the input data
for T in Tdata:
cp_exp = self.wilhoit.get_heat_capacity(T)
cp_act = wilhoit.get_heat_capacity(T)
self.assertAlmostEqual(cp_act, cp_exp, 4)
h_exp = self.wilhoit.get_enthalpy(T)
h_act = wilhoit.get_enthalpy(T)
self.assertAlmostEqual(h_act, h_exp, 3)
s_exp = self.wilhoit.get_entropy(T)
s_act = wilhoit.get_entropy(T)
self.assertAlmostEqual(s_act, s_exp, 4)
# Check that the fit reproduces the input parameters
# Since we're fitting to data generated from a Wilhoit (and since the
# fitting algorithm is linear least-squares), we should get the same
# Wilhoit parameters (with a small allowance for fitting error)
self.assertAlmostEqual(wilhoit.Cp0.value_si, self.wilhoit.Cp0.value_si,
6)
self.assertAlmostEqual(wilhoit.CpInf.value_si,
self.wilhoit.CpInf.value_si, 6)
self.assertAlmostEqual(wilhoit.a0, self.wilhoit.a0, 2)
self.assertAlmostEqual(wilhoit.a1, self.wilhoit.a1, 2)
self.assertAlmostEqual(wilhoit.a2, self.wilhoit.a2, 2)
self.assertAlmostEqual(wilhoit.a3, self.wilhoit.a3, 2)
self.assertAlmostEqual(wilhoit.B.value_si, self.wilhoit.B.value_si, 2)
self.assertAlmostEqual(wilhoit.H0.value_si, self.wilhoit.H0.value_si,
0)
self.assertAlmostEqual(wilhoit.S0.value_si, self.wilhoit.S0.value_si,
2)
class TestWilhoit(unittest.TestCase):
"""
Contains unit tests of the :class:`Wilhoit` class.
"""
def setUp(self):
"""
A function run before each unit test in this class.
"""
self.Cp0 = 4.0
self.CpInf = 21.5
self.a0 = 0.0977518
self.a1 = -16.3067
self.a2 = 26.2524
self.a3 = -12.6785
self.B = 1068.68
self.H0 = -94088. # -782.292 kJ/mol / constants.R
self.S0 = -118.46 # -984.932 J/mol*K / constants.R
self.Tmin = 300.
self.Tmax = 3000.
self.comment = 'C2H6'
self.wilhoit = Wilhoit(
Cp0=(self.Cp0 * constants.R, "J/(mol*K)"),
CpInf=(self.CpInf * constants.R, "J/(mol*K)"),
a0=self.a0,
a1=self.a1,
a2=self.a2,
a3=self.a3,
B=(self.B, "K"),
H0=(self.H0 * 0.001 * constants.R, "kJ/mol"),
S0=(self.S0 * constants.R, "J/(mol*K)"),
Tmin=(self.Tmin, "K"),
Tmax=(self.Tmax, "K"),
comment=self.comment,
)
def tearDown(self):
"""
Reset the database & liquid parameters for solution
"""
import rmgpy.data.rmg
rmgpy.data.rmg.database = None
def test_cp0(self):
"""
Test that the Wilhoit Cp0 property was properly set.
"""
self.assertAlmostEqual(self.wilhoit.Cp0.value_si / constants.R,
self.Cp0, 6)
def test_cp_inf(self):
"""
Test that the Wilhoit CpInf property was properly set.
"""
self.assertAlmostEqual(self.wilhoit.CpInf.value_si / constants.R,
self.CpInf, 6)
def test_a0(self):
"""
Test that the Wilhoit a0 property was properly set.
"""
self.assertAlmostEqual(self.wilhoit.a0, self.a0, 6)
def test_a1(self):
"""
Test that the Wilhoit a1 property was properly set.
"""
self.assertAlmostEqual(self.wilhoit.a1, self.a1, 6)
def test_a2(self):
"""
Test that the Wilhoit a2 property was properly set.
"""
self.assertAlmostEqual(self.wilhoit.a2, self.a2, 6)
def test_a3(self):
"""
Test that the Wilhoit a3 property was properly set.
"""
self.assertAlmostEqual(self.wilhoit.a3, self.a3, 6)
def test_b(self):
"""
Test that the Wilhoit B property was properly set.
"""
self.assertAlmostEqual(self.wilhoit.B.value_si, self.B, 6)
def test_h0(self):
"""
Test that the Wilhoit H0 property was properly set.
"""
self.assertAlmostEqual(self.wilhoit.H0.value_si / constants.R, self.H0,
6)
def test_s0(self):
"""
Test that the Wilhoit S0 property was properly set.
"""
self.assertAlmostEqual(self.wilhoit.S0.value_si / constants.R, self.S0,
6)
def test_temperature_min(self):
"""
Test that the Wilhoit Tmin property was properly set.
"""
self.assertAlmostEqual(self.wilhoit.Tmin.value_si, self.Tmin, 6)
def test_temperature_max(self):
"""
Test that the Wilhoit Tmax property was properly set.
"""
self.assertAlmostEqual(self.wilhoit.Tmax.value_si, self.Tmax, 6)
def test_e0(self):
"""
Test that the Wilhoit E0 property is properly calculated from Enthalpy at 0.001 K
"""
self.assertAlmostEqual(self.wilhoit.E0.value_si,
self.wilhoit.get_enthalpy(0.001), 1)
def test_comment(self):
"""
Test that the Wilhoit comment property was properly set.
"""
self.assertEqual(self.wilhoit.comment, self.comment)
def test_is_temperature_valid(self):
"""
Test the Wilhoit.is_temperature_valid() method.
"""
Tdata = [200, 400, 600, 800, 1000, 1200, 1400, 1600, 1800, 2000]
valid_data = [
False, True, True, True, True, True, True, True, True, True
]
for T, valid in zip(Tdata, valid_data):
valid0 = self.wilhoit.is_temperature_valid(T)
self.assertEqual(valid0, valid)
def test_get_heat_capacity(self):
"""
Test the Wilhoit.get_heat_capacity() method.
"""
Tlist = np.array(
[200, 400, 600, 800, 1000, 1200, 1400, 1600, 1800, 2000])
cp_exp_list = np.array([
5.12003, 7.80327, 10.5528, 12.8323, 14.6013, 15.9511, 16.9842,
17.7837, 18.4114, 18.9117
]) * constants.R
for T, cp_exp in zip(Tlist, cp_exp_list):
cp_act = self.wilhoit.get_heat_capacity(T)
self.assertAlmostEqual(
cp_exp / cp_act, 1.0, 3,
'{0} != {1} within 3 places'.format(cp_exp, cp_act))
def test_get_enthalpy(self):
"""
Test the Wilhoit.get_enthalpy() method.
"""
Tlist = np.array(
[200, 400, 600, 800, 1000, 1200, 1400, 1600, 1800, 2000])
h_exp_list = np.array([
-51.9303, -22.7609, -12.1050, -6.14444, -2.16433, 0.747500,
2.99646, 4.79698, 6.27618, 7.51564
]) * constants.R * Tlist
for T, h_exp in zip(Tlist, h_exp_list):
h_act = self.wilhoit.get_enthalpy(T)
self.assertAlmostEqual(h_exp / h_act, 1.0, 3,
'{0} != {1}'.format(h_exp, h_act))
def test_get_entropy(self):
"""
Test the Wilhoit.get_entropy() method.
"""
Tlist = np.array(
[200, 400, 600, 800, 1000, 1200, 1400, 1600, 1800, 2000])
s_exp_list = np.array([
25.3095, 29.6445, 33.3398, 36.7006, 39.7629, 42.5499, 45.0898,
47.4122, 49.5445, 51.5112
]) * constants.R
for T, s_exp in zip(Tlist, s_exp_list):
s_act = self.wilhoit.get_entropy(T)
self.assertAlmostEqual(s_exp / s_act, 1.0, 4,
'{0} != {1}'.format(s_exp, s_act))
def test_get_free_energy(self):
"""
Test the Wilhoit.get_free_energy() method.
"""
Tlist = np.array(
[200, 400, 600, 800, 1000, 1200, 1400, 1600, 1800, 2000])
for T in Tlist:
g_exp = self.wilhoit.get_enthalpy(
T) - T * self.wilhoit.get_entropy(T)
g_act = self.wilhoit.get_free_energy(T)
self.assertAlmostEqual(g_exp / g_act, 1.0, 4,
'{0} != {1}'.format(g_exp, g_act))
def test_pickle(self):
"""
Test that a Wilhoit object can be pickled and unpickled with no loss
of information.
"""
import pickle
wilhoit = pickle.loads(pickle.dumps(self.wilhoit))
self.assertAlmostEqual(self.wilhoit.Cp0.value, wilhoit.Cp0.value, 4)
self.assertEqual(self.wilhoit.Cp0.units, wilhoit.Cp0.units)
self.assertAlmostEqual(self.wilhoit.CpInf.value, wilhoit.CpInf.value,
3)
self.assertEqual(self.wilhoit.CpInf.units, wilhoit.CpInf.units)
self.assertAlmostEqual(self.wilhoit.a0, wilhoit.a0, 4)
self.assertAlmostEqual(self.wilhoit.a1, wilhoit.a1, 4)
self.assertAlmostEqual(self.wilhoit.a2, wilhoit.a2, 4)
self.assertAlmostEqual(self.wilhoit.a3, wilhoit.a3, 4)
self.assertAlmostEqual(self.wilhoit.B.value, wilhoit.B.value, 4)
self.assertEqual(self.wilhoit.B.units, wilhoit.B.units)
self.assertAlmostEqual(self.wilhoit.H0.value, wilhoit.H0.value, 4)
self.assertEqual(self.wilhoit.H0.units, wilhoit.H0.units)
self.assertAlmostEqual(self.wilhoit.S0.value, wilhoit.S0.value, 3)
self.assertEqual(self.wilhoit.S0.units, wilhoit.S0.units)
self.assertAlmostEqual(self.wilhoit.Tmin.value, wilhoit.Tmin.value, 4)
self.assertEqual(self.wilhoit.Tmin.units, wilhoit.Tmin.units)
self.assertAlmostEqual(self.wilhoit.Tmax.value, wilhoit.Tmax.value, 4)
self.assertEqual(self.wilhoit.Tmax.units, wilhoit.Tmax.units)
self.assertAlmostEqual(self.wilhoit.E0.value, wilhoit.E0.value, 4)
self.assertEqual(self.wilhoit.E0.units, wilhoit.E0.units)
self.assertEqual(self.wilhoit.comment, wilhoit.comment)
def test_repr(self):
"""
Test that a Wilhoit object can be reconstructed from its repr() output
with no loss of information.
"""
namespace = {}
exec('wilhoit = {0!r}'.format(self.wilhoit), globals(), namespace)
self.assertIn('wilhoit', namespace)
wilhoit = namespace['wilhoit']
self.assertAlmostEqual(self.wilhoit.Cp0.value, wilhoit.Cp0.value, 4)
self.assertEqual(self.wilhoit.Cp0.units, wilhoit.Cp0.units)
self.assertAlmostEqual(self.wilhoit.CpInf.value, wilhoit.CpInf.value,
3)
self.assertEqual(self.wilhoit.CpInf.units, wilhoit.CpInf.units)
self.assertAlmostEqual(self.wilhoit.a0, wilhoit.a0, 4)
self.assertAlmostEqual(self.wilhoit.a1, wilhoit.a1, 4)
self.assertAlmostEqual(self.wilhoit.a2, wilhoit.a2, 4)
self.assertAlmostEqual(self.wilhoit.a3, wilhoit.a3, 4)
self.assertAlmostEqual(self.wilhoit.B.value, wilhoit.B.value, 4)
self.assertEqual(self.wilhoit.B.units, wilhoit.B.units)
self.assertAlmostEqual(self.wilhoit.H0.value, wilhoit.H0.value, 4)
self.assertEqual(self.wilhoit.H0.units, wilhoit.H0.units)
self.assertAlmostEqual(self.wilhoit.S0.value, wilhoit.S0.value, 3)
self.assertEqual(self.wilhoit.S0.units, wilhoit.S0.units)
self.assertAlmostEqual(self.wilhoit.Tmin.value, wilhoit.Tmin.value, 4)
self.assertEqual(self.wilhoit.Tmin.units, wilhoit.Tmin.units)
self.assertAlmostEqual(self.wilhoit.Tmax.value, wilhoit.Tmax.value, 4)
self.assertEqual(self.wilhoit.Tmax.units, wilhoit.Tmax.units)
self.assertAlmostEqual(self.wilhoit.E0.value, wilhoit.E0.value, 1)
self.assertEqual(self.wilhoit.E0.units, wilhoit.E0.units)
self.assertEqual(self.wilhoit.comment, wilhoit.comment)
def test_fit_to_data(self):
"""
Test the Wilhoit.fit_to_data() method.
"""
h298 = self.wilhoit.get_enthalpy(298)
s298 = self.wilhoit.get_entropy(298)
Tdata = np.array([300., 400., 500., 600., 800., 1000., 1500.])
cp_data = np.zeros_like(Tdata)
for i in range(Tdata.shape[0]):
cp_data[i] = self.wilhoit.get_heat_capacity(Tdata[i])
cp_0 = self.Cp0 * constants.R
cp_inf = self.CpInf * constants.R
# Fit the Wilhoit polynomial to the data
wilhoit = Wilhoit().fit_to_data(Tdata, cp_data, cp_0, cp_inf, h298,
s298)
# Check that the fit reproduces the input data
for T in Tdata:
cp_exp = self.wilhoit.get_heat_capacity(T)
cp_act = wilhoit.get_heat_capacity(T)
self.assertAlmostEqual(cp_act, cp_exp, 4)
h_exp = self.wilhoit.get_enthalpy(T)
h_act = wilhoit.get_enthalpy(T)
self.assertAlmostEqual(h_act, h_exp, 3)
s_exp = self.wilhoit.get_entropy(T)
s_act = wilhoit.get_entropy(T)
self.assertAlmostEqual(s_act, s_exp, 4)
# Check that the fit reproduces the input parameters
# Since we're fitting to data generated from a Wilhoit (and since the
# fitting algorithm is linear least-squares), we should get the same
# Wilhoit parameters (with a small allowance for fitting error)
self.assertAlmostEqual(wilhoit.Cp0.value_si, self.wilhoit.Cp0.value_si,
6)
self.assertAlmostEqual(wilhoit.CpInf.value_si,
self.wilhoit.CpInf.value_si, 6)
self.assertAlmostEqual(wilhoit.a0, self.wilhoit.a0, 2)
self.assertAlmostEqual(wilhoit.a1, self.wilhoit.a1, 2)
self.assertAlmostEqual(wilhoit.a2, self.wilhoit.a2, 2)
self.assertAlmostEqual(wilhoit.a3, self.wilhoit.a3, 2)
self.assertAlmostEqual(wilhoit.B.value_si, self.wilhoit.B.value_si, 2)
self.assertAlmostEqual(wilhoit.H0.value_si, self.wilhoit.H0.value_si,
0)
self.assertAlmostEqual(wilhoit.S0.value_si, self.wilhoit.S0.value_si,
2)
def test_to_wilhoit(self):
"""
Test if the entropy computed from other thermo implementations is close to what Wilhoit computes.
"""
from rmgpy import settings
from rmgpy.data.rmg import RMGDatabase
from rmgpy.species import Species
# Load databases
database = RMGDatabase()
database.load_thermo(os.path.join(settings['database.directory'],
'thermo'),
thermo_libraries=['Narayanaswamy'])
database.load_solvation(
os.path.join(settings['database.directory'], 'solvation'))
spc = Species().from_smiles('CC')
spc.get_thermo_data()
T = 1350. # not 298K!
# nasa to wilhoit
nasa = spc.thermo
s_nasa = nasa.get_entropy(T)
nasa_to_wh = nasa.to_wilhoit()
s_nasa_to_wh = nasa_to_wh.get_entropy(T)
self.assertAlmostEqual(s_nasa, s_nasa_to_wh, -1)
self.assertEqual(nasa.comment, nasa_to_wh.comment)
# wilhoit to nasa conversion done in nasaTest.py
# thermo data to wilhoit:
td = nasa.to_thermo_data()
s_td = td.get_entropy(T)
wilhoit = td.to_wilhoit(B=1000.)
s_wh = wilhoit.get_entropy(T)
self.assertAlmostEqual(s_td, s_wh, -1)
self.assertEqual(td.comment, wilhoit.comment)
# wilhoit back to thermodata
td = wilhoit.to_thermo_data()
s_td = td.get_entropy(T)
self.assertAlmostEqual(s_td, s_wh, -1)
self.assertEqual(td.comment, wilhoit.comment)
def test_wilhoit_as_dict(self):
"""
Test that a Wilhoit object can be converted to a dictionary representation properly
"""
wilhoit_dict = self.wilhoit.as_dict()
self.assertEqual(
wilhoit_dict, {
'comment': 'C2H6',
'B': {
'units': 'K',
'class': 'ScalarQuantity',
'value': 1068.68
},
'Tmin': {
'units': 'K',
'class': 'ScalarQuantity',
'value': 300.0
},
'H0': {
'units': 'kJ/mol',
'class': 'ScalarQuantity',
'value': -782.292041536
},
'Tmax': {
'units': 'K',
'class': 'ScalarQuantity',
'value': 3000.0
},
'S0': {
'units': 'J/(mol*K)',
'class': 'ScalarQuantity',
'value': -984.93235312
},
'a1': -16.3067,
'a0': 0.0977518,
'a3': -12.6785,
'a2': 26.2524,
'Cp0': {
'units': 'J/(mol*K)',
'class': 'ScalarQuantity',
'value': 33.257888
},
'CpInf': {
'units': 'J/(mol*K)',
'class': 'ScalarQuantity',
'value': 178.76114800000002
},
'class': 'Wilhoit'
})
def test_make_wilhoit(self):
"""
Test that a Wilhoit object can be created from a dictionary representation
"""
wilhoit_dict = self.wilhoit.as_dict()
new_wilhoit = Wilhoit.__new__(Wilhoit)
class_dictionary = {
'ScalarQuantity': ScalarQuantity,
'Wilhoit': Wilhoit
}
new_wilhoit.make_object(wilhoit_dict, class_dictionary)
