Exemple #1
0
class TestNASA(unittest.TestCase):
    """
    Contains unit tests of the MultiNASA class.
    """
    def setUp(self):
        """
        A function run before each unit test in this class.
        """
        self.coeffs_low = [
            4.03055, -0.00214171, 4.90611e-05, -5.99027e-08, 2.38945e-11,
            -11257.6, 3.5613
        ]
        self.coeffs_high = [
            -0.307954, 0.0245269, -1.2413e-05, 3.07724e-09, -3.01467e-13,
            -10693, 22.628
        ]
        self.Tmin = 300.
        self.Tmax = 3000.
        self.Tint = 650.73
        self.E0 = -782292.  # J/mol.
        self.comment = "C2H6"
        self.nasa = NASA(
            polynomials=[
                NASAPolynomial(coeffs=self.coeffs_low,
                               Tmin=(self.Tmin, "K"),
                               Tmax=(self.Tint, "K")),
                NASAPolynomial(coeffs=self.coeffs_high,
                               Tmin=(self.Tint, "K"),
                               Tmax=(self.Tmax, "K")),
            ],
            Tmin=(self.Tmin, "K"),
            Tmax=(self.Tmax, "K"),
            E0=(self.E0, "J/mol"),
            comment=self.comment,
        )

    def tearDown(self):
        """
        Reset the database & liquid parameters for solution
        """
        import rmgpy.data.rmg
        rmgpy.data.rmg.database = None

    def test_poly_low(self):
        """
        Test that the NASA low-temperature polynomial was properly set.
        """
        self.assertEqual(len(self.nasa.poly1.coeffs), len(self.coeffs_low))
        for coeff0, coeff in zip(self.nasa.poly1.coeffs, self.coeffs_low):
            self.assertAlmostEqual(coeff / coeff0, 1.0, 6)
        self.assertEqual(self.nasa.poly1.Tmin.value_si, self.Tmin)
        self.assertEqual(self.nasa.poly1.Tmax.value_si, self.Tint)

    def test_poly_high(self):
        """
        Test that the NASA high-temperature polynomial was properly set.
        """
        self.assertEqual(len(self.nasa.poly2.coeffs), len(self.coeffs_high))
        for coeff0, coeff in zip(self.nasa.poly2.coeffs, self.coeffs_high):
            self.assertAlmostEqual(coeff / coeff0, 1.0, 6)
        self.assertEqual(self.nasa.poly2.Tmin.value_si, self.Tint)
        self.assertEqual(self.nasa.poly2.Tmax.value_si, self.Tmax)

    def test_temperature_min(self):
        """
        Test that the NASA Tmin property was properly set.
        """
        self.assertAlmostEqual(
            self.nasa.Tmin.value_si / self.Tmin, 1.0, 6,
            '{0} != {1} within 6 places'.format(self.nasa.Tmin, self.Tmin))

    def test_temperature_max(self):
        """
        Test that the NASA Tmax property was properly set.
        """
        self.assertAlmostEqual(
            self.nasa.Tmax.value_si / self.Tmax, 1.0, 6,
            '{0} != {1} within 6 places'.format(self.nasa.Tmax, self.Tmax))

    def test_e0(self):
        """
        Test that the NASA E0 property was properly set.
        """
        self.assertAlmostEqual(
            self.nasa.E0.value_si / self.E0, 1.0, 6,
            '{0} != {1} within 6 places'.format(self.nasa.Tmax, self.Tmax))

    def test_comment(self):
        """
        Test that the NASA comment property was properly set.
        """
        self.assertEqual(self.nasa.comment, self.comment)

    def test_is_temperature_valid(self):
        """
        Test the NASA.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.nasa.is_temperature_valid(T)
            self.assertEqual(valid0, valid)

    def test_get_heat_capacity(self):
        """
        Test the NASA.get_heat_capacity() method.
        """
        Tlist = np.array([400, 600, 800, 1000, 1200, 1400, 1600, 1800, 2000])
        cp_exp_list = np.array([
            7.80157, 10.5653, 12.8213, 14.5817, 15.9420, 16.9861, 17.78645,
            18.4041, 18.8883
        ]) * constants.R
        for T, cp_exp in zip(Tlist, cp_exp_list):
            cp_act = self.nasa.get_heat_capacity(T)
            self.assertAlmostEqual(cp_exp / cp_act, 1.0, 4,
                                   '{0} != {1}'.format(cp_exp, cp_act))

    def test_get_enthalpy(self):
        """
        Test the NASA.get_enthalpy() method.
        """
        Tlist = np.array([400, 600, 800, 1000, 1200, 1400, 1600, 1800, 2000])
        h_exp_list = np.array([
            -22.7613, -12.1027, -6.14236, -2.16615, 0.743456, 2.99256, 4.79397,
            6.27334, 7.51156
        ]) * constants.R * Tlist
        for T, h_exp in zip(Tlist, h_exp_list):
            h_act = self.nasa.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 NASA.get_entropy() method.
        """
        Tlist = np.array([400, 600, 800, 1000, 1200, 1400, 1600, 1800, 2000])
        s_exp_list = np.array([
            29.6534, 33.3516, 36.7131, 39.7715, 42.5557, 45.0952, 47.4179,
            49.5501, 51.5152
        ]) * constants.R
        for T, s_exp in zip(Tlist, s_exp_list):
            s_act = self.nasa.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 NASA.get_free_energy() method.
        """
        Tlist = np.array([400, 600, 800, 1000, 1200, 1400, 1600, 1800, 2000])
        for T in Tlist:
            g_exp = self.nasa.get_enthalpy(T) - T * self.nasa.get_entropy(T)
            g_act = self.nasa.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 NASA object can be pickled and unpickled with no loss of
        information.
        """
        import pickle
        nasa = pickle.loads(pickle.dumps(self.nasa))
        self.assertEqual(len(self.nasa.poly1.coeffs), len(nasa.poly1.coeffs))
        for coeff0, coeff in zip(self.nasa.poly1.coeffs, nasa.poly1.coeffs):
            self.assertAlmostEqual(coeff / coeff0, 1.0, 6)
        self.assertEqual(self.nasa.poly1.Tmin.value, nasa.poly1.Tmin.value)
        self.assertEqual(self.nasa.poly1.Tmin.units, nasa.poly1.Tmin.units)
        self.assertEqual(self.nasa.poly1.Tmax.value, nasa.poly1.Tmax.value)
        self.assertEqual(self.nasa.poly1.Tmax.units, nasa.poly1.Tmax.units)
        self.assertEqual(self.nasa.poly1.comment, nasa.poly1.comment)
        self.assertEqual(len(self.nasa.poly2.coeffs), len(nasa.poly2.coeffs))
        for coeff0, coeff in zip(self.nasa.poly2.coeffs, nasa.poly2.coeffs):
            self.assertAlmostEqual(coeff / coeff0, 1.0, 6)
        self.assertEqual(self.nasa.poly2.Tmin.value, nasa.poly2.Tmin.value)
        self.assertEqual(self.nasa.poly2.Tmin.units, nasa.poly2.Tmin.units)
        self.assertEqual(self.nasa.poly2.Tmax.value, nasa.poly2.Tmax.value)
        self.assertEqual(self.nasa.poly2.Tmax.units, nasa.poly2.Tmax.units)
        self.assertEqual(self.nasa.poly2.comment, nasa.poly2.comment)
        self.assertEqual(self.nasa.Tmin.value, nasa.Tmin.value)
        self.assertEqual(self.nasa.Tmin.units, nasa.Tmin.units)
        self.assertEqual(self.nasa.Tmax.value, nasa.Tmax.value)
        self.assertEqual(self.nasa.Tmax.units, nasa.Tmax.units)
        self.assertEqual(self.nasa.E0.value, nasa.E0.value)
        self.assertEqual(self.nasa.E0.units, nasa.E0.units)
        self.assertEqual(self.nasa.comment, nasa.comment)

    def test_repr(self):
        """
        Test that a NASA object can be reconstructed from its repr() output
        with no loss of information.
        """
        namespace = {}
        exec('nasa = {0!r}'.format(self.nasa), globals(), namespace)
        self.assertIn('nasa', namespace)
        nasa = namespace['nasa']
        self.assertEqual(len(self.nasa.poly1.coeffs), len(nasa.poly1.coeffs))
        for coeff0, coeff in zip(self.nasa.poly1.coeffs, nasa.poly1.coeffs):
            self.assertAlmostEqual(coeff / coeff0, 1.0, 6)
        self.assertEqual(self.nasa.poly1.Tmin.value, nasa.poly1.Tmin.value)
        self.assertEqual(self.nasa.poly1.Tmin.units, nasa.poly1.Tmin.units)
        self.assertEqual(self.nasa.poly1.Tmax.value, nasa.poly1.Tmax.value)
        self.assertEqual(self.nasa.poly1.Tmax.units, nasa.poly1.Tmax.units)
        self.assertEqual(self.nasa.poly1.comment, nasa.poly1.comment)
        self.assertEqual(len(self.nasa.poly2.coeffs), len(nasa.poly2.coeffs))
        for coeff0, coeff in zip(self.nasa.poly2.coeffs, nasa.poly2.coeffs):
            self.assertAlmostEqual(coeff / coeff0, 1.0, 6)
        self.assertEqual(self.nasa.poly2.Tmin.value, nasa.poly2.Tmin.value)
        self.assertEqual(self.nasa.poly2.Tmin.units, nasa.poly2.Tmin.units)
        self.assertEqual(self.nasa.poly2.Tmax.value, nasa.poly2.Tmax.value)
        self.assertEqual(self.nasa.poly2.Tmax.units, nasa.poly2.Tmax.units)
        self.assertEqual(self.nasa.poly2.comment, nasa.poly2.comment)
        self.assertEqual(self.nasa.Tmin.value, nasa.Tmin.value)
        self.assertEqual(self.nasa.Tmin.units, nasa.Tmin.units)
        self.assertEqual(self.nasa.Tmax.value, nasa.Tmax.value)
        self.assertEqual(self.nasa.Tmax.units, nasa.Tmax.units)
        self.assertEqual(self.nasa.E0.value, nasa.E0.value)
        self.assertEqual(self.nasa.E0.units, nasa.E0.units)
        self.assertEqual(self.nasa.comment, nasa.comment)

    def test_to_cantera(self):
        """
        Test that conversion to a Cantera NasaPoly2 object works
        """
        nasapoly2 = self.nasa.to_cantera()
        # NasaPoly2 units use J/kmol rather than J/mol
        self.assertAlmostEqual(self.nasa.get_enthalpy(900),
                               nasapoly2.h(900) / 1000, 1)
        self.assertAlmostEqual(self.nasa.get_entropy(700),
                               nasapoly2.s(700) / 1000, 1)

    def test_to_nasa(self):
        """
        Test if the entropy computed from other thermo implementations is close to what NASA 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 thermodata
        nasa = spc.thermo
        s_nasa = nasa.get_entropy(T)

        td = nasa.to_thermo_data()
        s_td = td.get_entropy(T)

        self.assertAlmostEqual(s_nasa, s_td, -1)
        self.assertEqual(td.comment, nasa.comment)

        # thermodata to nasa
        nasa = td.to_nasa(Tmin=100.0, Tmax=5000.0, Tint=1000.0)
        s_nasa = nasa.get_entropy(T)

        self.assertAlmostEqual(s_nasa, s_td, -1)
        self.assertEqual(td.comment, nasa.comment)

        # wilhoit to nasa
        wilhoit = nasa.to_wilhoit()
        nasa = wilhoit.to_nasa(Tmin=100.0, Tmax=5000.0, Tint=1000.0)
        s_nasa = nasa.get_entropy(T)

        self.assertAlmostEqual(s_nasa, s_td, -1)
        self.assertEqual(wilhoit.comment, nasa.comment)

        # nasa to wilhoi performed in wilhoitTest

    def test_nasa_as_dict_full(self):
        """
        Test that NASA.as_dict functions properly with all attributes
        """
        nasa_dict = self.nasa.as_dict()
        self.assertEqual(nasa_dict['E0']['value'], self.E0)
        self.assertEqual(nasa_dict['Tmin']['value'], self.Tmin)
        self.assertEqual(nasa_dict['Tmax']['value'], self.Tmax)
        self.assertEqual(nasa_dict['comment'], self.comment)
        self.assertTupleEqual(
            tuple(nasa_dict['polynomials']['polynomial1']['coeffs']['object']),
            tuple(self.coeffs_low))
        self.assertTupleEqual(
            tuple(nasa_dict['polynomials']['polynomial2']['coeffs']['object']),
            tuple(self.coeffs_high))
        self.assertEqual(
            nasa_dict['polynomials']['polynomial1']['Tmin']['value'],
            self.Tmin)
        self.assertEqual(
            nasa_dict['polynomials']['polynomial1']['Tmax']['value'],
            self.Tint)
        self.assertEqual(
            nasa_dict['polynomials']['polynomial2']['Tmin']['value'],
            self.Tint)
        self.assertEqual(
            nasa_dict['polynomials']['polynomial2']['Tmax']['value'],
            self.Tmax)

    def test_nasa_as_dict_minimal(self):
        """
        Test that NASA.as_dict does not contain empty, optional attributes
        """
        nasa_dict = NASA().as_dict()
        keys = list(nasa_dict.keys())
        self.assertNotIn('Tmin', keys)
        self.assertNotIn('Tmax', keys)
        self.assertNotIn('E0', keys)
        self.assertNotIn('Cp0', keys)
        self.assertNotIn('CpInf', keys)
        self.assertNotIn('label', keys)
        self.assertNotIn('comment', keys)

    def test_nasa_polynomial_as_dict(self):
        """
        Test that NASAPolynomial.as_dict returns all non-empty, non-redundant attributes properly.
        """
        nasa_poly_dict = self.nasa.polynomials[0].as_dict()
        self.assertEqual(
            nasa_poly_dict, {
                'coeffs': {
                    'object': [
                        4.03055, -0.00214171, 4.90611e-05, -5.99027e-08,
                        2.38945e-11, -11257.6, 3.5613
                    ],
                    'class':
                    'np_array'
                },
                'Tmax': {
                    'units': 'K',
                    'class': 'ScalarQuantity',
                    'value': 650.73
                },
                'Tmin': {
                    'units': 'K',
                    'class': 'ScalarQuantity',
                    'value': 300.0
                },
                'class': 'NASAPolynomial'
            })

    def test_make_nasa(self):
        """
        Test that a NASA object can be reconstructed from a dictionary (also test NASAPolynomial by extension)
        """
        nasa_dict = self.nasa.as_dict()
        new_nasa = NASA.__new__(NASA)
        class_dictionary = {
            'ScalarQuantity': ScalarQuantity,
            'np_array': np.array,
            'NASA': NASA,
            'NASAPolynomial': NASAPolynomial,
        }

        new_nasa.make_object(nasa_dict, class_dictionary)
Exemple #2
0
class TestNASA(unittest.TestCase):
    """
    Contains unit tests of the MultiNASA class.
    """
    def setUp(self):
        """
        A function run before each unit test in this class.
        """
        self.coeffs_low = [
            4.03055, -0.00214171, 4.90611e-05, -5.99027e-08, 2.38945e-11,
            -11257.6, 3.5613
        ]
        self.coeffs_high = [
            -0.307954, 0.0245269, -1.2413e-05, 3.07724e-09, -3.01467e-13,
            -10693, 22.628
        ]
        self.Tmin = 300.
        self.Tmax = 3000.
        self.Tint = 650.73
        self.E0 = -782292.  # J/mol.
        self.comment = "C2H6"
        self.nasa = NASA(
            polynomials=[
                NASAPolynomial(coeffs=self.coeffs_low,
                               Tmin=(self.Tmin, "K"),
                               Tmax=(self.Tint, "K")),
                NASAPolynomial(coeffs=self.coeffs_high,
                               Tmin=(self.Tint, "K"),
                               Tmax=(self.Tmax, "K")),
            ],
            Tmin=(self.Tmin, "K"),
            Tmax=(self.Tmax, "K"),
            E0=(self.E0, "J/mol"),
            comment=self.comment,
        )

    def tearDown(self):
        """
        Reset the database & liquid parameters for solution
        """
        import rmgpy.data.rmg
        rmgpy.data.rmg.database = None

    def test_polyLow(self):
        """
        Test that the NASA low-temperature polynomial was properly set.
        """
        self.assertEqual(len(self.nasa.poly1.coeffs), len(self.coeffs_low))
        for coeff0, coeff in zip(self.nasa.poly1.coeffs, self.coeffs_low):
            self.assertAlmostEqual(coeff / coeff0, 1.0, 6)
        self.assertEqual(self.nasa.poly1.Tmin.value_si, self.Tmin)
        self.assertEqual(self.nasa.poly1.Tmax.value_si, self.Tint)

    def test_polyHigh(self):
        """
        Test that the NASA high-temperature polynomial was properly set.
        """
        self.assertEqual(len(self.nasa.poly2.coeffs), len(self.coeffs_high))
        for coeff0, coeff in zip(self.nasa.poly2.coeffs, self.coeffs_high):
            self.assertAlmostEqual(coeff / coeff0, 1.0, 6)
        self.assertEqual(self.nasa.poly2.Tmin.value_si, self.Tint)
        self.assertEqual(self.nasa.poly2.Tmax.value_si, self.Tmax)

    def test_Tmin(self):
        """
        Test that the NASA Tmin property was properly set.
        """
        self.assertAlmostEqual(
            self.nasa.Tmin.value_si / self.Tmin, 1.0, 6,
            '{0} != {1} within 6 places'.format(self.nasa.Tmin, self.Tmin))

    def test_Tmax(self):
        """
        Test that the NASA Tmax property was properly set.
        """
        self.assertAlmostEqual(
            self.nasa.Tmax.value_si / self.Tmax, 1.0, 6,
            '{0} != {1} within 6 places'.format(self.nasa.Tmax, self.Tmax))

    def test_E0(self):
        """
        Test that the NASA E0 property was properly set.
        """
        self.assertAlmostEqual(
            self.nasa.E0.value_si / self.E0, 1.0, 6,
            '{0} != {1} within 6 places'.format(self.nasa.Tmax, self.Tmax))

    def test_Comment(self):
        """
        Test that the NASA comment property was properly set.
        """
        self.assertEqual(self.nasa.comment, self.comment)

    def test_isTemperatureValid(self):
        """
        Test the NASA.isTemperatureValid() method.
        """
        Tdata = [200, 400, 600, 800, 1000, 1200, 1400, 1600, 1800, 2000]
        validdata = [
            False, True, True, True, True, True, True, True, True, True
        ]
        for T, valid in zip(Tdata, validdata):
            valid0 = self.nasa.isTemperatureValid(T)
            self.assertEqual(valid0, valid)

    def test_getHeatCapacity(self):
        """
        Test the NASA.getHeatCapacity() method.
        """
        Tlist = numpy.array(
            [400, 600, 800, 1000, 1200, 1400, 1600, 1800, 2000])
        Cpexplist = numpy.array([
            7.80157, 10.5653, 12.8213, 14.5817, 15.9420, 16.9861, 17.78645,
            18.4041, 18.8883
        ]) * constants.R
        for T, Cpexp in zip(Tlist, Cpexplist):
            Cpact = self.nasa.getHeatCapacity(T)
            self.assertAlmostEqual(Cpexp / Cpact, 1.0, 4,
                                   '{0} != {1}'.format(Cpexp, Cpact))

    def test_getEnthalpy(self):
        """
        Test the NASA.getEnthalpy() method.
        """
        Tlist = numpy.array(
            [400, 600, 800, 1000, 1200, 1400, 1600, 1800, 2000])
        Hexplist = numpy.array([
            -22.7613, -12.1027, -6.14236, -2.16615, 0.743456, 2.99256, 4.79397,
            6.27334, 7.51156
        ]) * constants.R * Tlist
        for T, Hexp in zip(Tlist, Hexplist):
            Hact = self.nasa.getEnthalpy(T)
            self.assertAlmostEqual(Hexp / Hact, 1.0, 3,
                                   '{0} != {1}'.format(Hexp, Hact))

    def test_getEntropy(self):
        """
        Test the NASA.getEntropy() method.
        """
        Tlist = numpy.array(
            [400, 600, 800, 1000, 1200, 1400, 1600, 1800, 2000])
        Sexplist = numpy.array([
            29.6534, 33.3516, 36.7131, 39.7715, 42.5557, 45.0952, 47.4179,
            49.5501, 51.5152
        ]) * constants.R
        for T, Sexp in zip(Tlist, Sexplist):
            Sact = self.nasa.getEntropy(T)
            self.assertAlmostEqual(Sexp / Sact, 1.0, 4,
                                   '{0} != {1}'.format(Sexp, Sact))

    def test_getFreeEnergy(self):
        """
        Test the NASA.getFreeEnergy() method.
        """
        Tlist = numpy.array(
            [400, 600, 800, 1000, 1200, 1400, 1600, 1800, 2000])
        for T in Tlist:
            Gexp = self.nasa.getEnthalpy(T) - T * self.nasa.getEntropy(T)
            Gact = self.nasa.getFreeEnergy(T)
            self.assertAlmostEqual(Gexp / Gact, 1.0, 4,
                                   '{0} != {1}'.format(Gexp, Gact))

    def test_pickle(self):
        """
        Test that a NASA object can be pickled and unpickled with no loss of
        information.
        """
        import cPickle
        nasa = cPickle.loads(cPickle.dumps(self.nasa))
        self.assertEqual(len(self.nasa.poly1.coeffs), len(nasa.poly1.coeffs))
        for coeff0, coeff in zip(self.nasa.poly1.coeffs, nasa.poly1.coeffs):
            self.assertAlmostEqual(coeff / coeff0, 1.0, 6)
        self.assertEqual(self.nasa.poly1.Tmin.value, nasa.poly1.Tmin.value)
        self.assertEqual(self.nasa.poly1.Tmin.units, nasa.poly1.Tmin.units)
        self.assertEqual(self.nasa.poly1.Tmax.value, nasa.poly1.Tmax.value)
        self.assertEqual(self.nasa.poly1.Tmax.units, nasa.poly1.Tmax.units)
        self.assertEqual(self.nasa.poly1.comment, nasa.poly1.comment)
        self.assertEqual(len(self.nasa.poly2.coeffs), len(nasa.poly2.coeffs))
        for coeff0, coeff in zip(self.nasa.poly2.coeffs, nasa.poly2.coeffs):
            self.assertAlmostEqual(coeff / coeff0, 1.0, 6)
        self.assertEqual(self.nasa.poly2.Tmin.value, nasa.poly2.Tmin.value)
        self.assertEqual(self.nasa.poly2.Tmin.units, nasa.poly2.Tmin.units)
        self.assertEqual(self.nasa.poly2.Tmax.value, nasa.poly2.Tmax.value)
        self.assertEqual(self.nasa.poly2.Tmax.units, nasa.poly2.Tmax.units)
        self.assertEqual(self.nasa.poly2.comment, nasa.poly2.comment)
        self.assertEqual(self.nasa.Tmin.value, nasa.Tmin.value)
        self.assertEqual(self.nasa.Tmin.units, nasa.Tmin.units)
        self.assertEqual(self.nasa.Tmax.value, nasa.Tmax.value)
        self.assertEqual(self.nasa.Tmax.units, nasa.Tmax.units)
        self.assertEqual(self.nasa.E0.value, nasa.E0.value)
        self.assertEqual(self.nasa.E0.units, nasa.E0.units)
        self.assertEqual(self.nasa.comment, nasa.comment)

    def test_repr(self):
        """
        Test that a NASA object can be reconstructed from its repr() output
        with no loss of information.
        """
        nasa = None
        exec('nasa = {0!r}'.format(self.nasa))
        self.assertEqual(len(self.nasa.poly1.coeffs), len(nasa.poly1.coeffs))
        for coeff0, coeff in zip(self.nasa.poly1.coeffs, nasa.poly1.coeffs):
            self.assertAlmostEqual(coeff / coeff0, 1.0, 6)
        self.assertEqual(self.nasa.poly1.Tmin.value, nasa.poly1.Tmin.value)
        self.assertEqual(self.nasa.poly1.Tmin.units, nasa.poly1.Tmin.units)
        self.assertEqual(self.nasa.poly1.Tmax.value, nasa.poly1.Tmax.value)
        self.assertEqual(self.nasa.poly1.Tmax.units, nasa.poly1.Tmax.units)
        self.assertEqual(self.nasa.poly1.comment, nasa.poly1.comment)
        self.assertEqual(len(self.nasa.poly2.coeffs), len(nasa.poly2.coeffs))
        for coeff0, coeff in zip(self.nasa.poly2.coeffs, nasa.poly2.coeffs):
            self.assertAlmostEqual(coeff / coeff0, 1.0, 6)
        self.assertEqual(self.nasa.poly2.Tmin.value, nasa.poly2.Tmin.value)
        self.assertEqual(self.nasa.poly2.Tmin.units, nasa.poly2.Tmin.units)
        self.assertEqual(self.nasa.poly2.Tmax.value, nasa.poly2.Tmax.value)
        self.assertEqual(self.nasa.poly2.Tmax.units, nasa.poly2.Tmax.units)
        self.assertEqual(self.nasa.poly2.comment, nasa.poly2.comment)
        self.assertEqual(self.nasa.Tmin.value, nasa.Tmin.value)
        self.assertEqual(self.nasa.Tmin.units, nasa.Tmin.units)
        self.assertEqual(self.nasa.Tmax.value, nasa.Tmax.value)
        self.assertEqual(self.nasa.Tmax.units, nasa.Tmax.units)
        self.assertEqual(self.nasa.E0.value, nasa.E0.value)
        self.assertEqual(self.nasa.E0.units, nasa.E0.units)
        self.assertEqual(self.nasa.comment, nasa.comment)

    def test_toCantera(self):
        """
        Test that conversion to a Cantera NasaPoly2 object works
        """
        nasapoly2 = self.nasa.toCantera()
        # NasaPoly2 units use J/kmol rather than J/mol
        self.assertAlmostEqual(self.nasa.getEnthalpy(900),
                               nasapoly2.h(900) / 1000, 1)
        self.assertAlmostEqual(self.nasa.getEntropy(700),
                               nasapoly2.s(700) / 1000, 1)

    def testToNASA(self):
        """
        Test if the entropy computed from other thermo implementations is close to what NASA computes.
        """

        from rmgpy import settings
        from rmgpy.data.rmg import RMGDatabase, database
        from rmgpy.species import Species

        # Load databases
        database = RMGDatabase()
        database.loadThermo(os.path.join(settings['database.directory'],
                                         'thermo'),
                            thermoLibraries=['Narayanaswamy'])
        database.loadSolvation(
            os.path.join(settings['database.directory'], 'solvation'))

        spc = Species().fromSMILES('CC')
        spc.getThermoData()

        T = 1350.  # not 298K!

        # nasa to thermodata
        nasa = spc.thermo
        Snasa = nasa.getEntropy(T)

        td = nasa.toThermoData()
        Std = td.getEntropy(T)

        self.assertAlmostEqual(Snasa, Std, -1)
        self.assertEqual(td.comment, nasa.comment)

        # thermodata to nasa
        nasa = td.toNASA(Tmin=100.0, Tmax=5000.0, Tint=1000.0)
        Snasa = nasa.getEntropy(T)

        self.assertAlmostEqual(Snasa, Std, -1)
        self.assertEqual(td.comment, nasa.comment)

        # wilhoit to nasa
        wilhoit = nasa.toWilhoit()
        nasa = wilhoit.toNASA(Tmin=100.0, Tmax=5000.0, Tint=1000.0)
        Snasa = nasa.getEntropy(T)

        self.assertAlmostEqual(Snasa, Std, -1)
        self.assertEqual(wilhoit.comment, nasa.comment)

        # nasa to wilhoi performed in wilhoitTest

    def test_nasa_as_dict_full(self):
        """
        Test that NASA.as_dict functions properly with all attributes
        """
        nasa_dict = self.nasa.as_dict()
        self.assertEqual(nasa_dict['E0']['value'], self.E0)
        self.assertEqual(nasa_dict['Tmin']['value'], self.Tmin)
        self.assertEqual(nasa_dict['Tmax']['value'], self.Tmax)
        self.assertEqual(nasa_dict['comment'], self.comment)
        self.assertTupleEqual(
            tuple(nasa_dict['polynomials']['polynomial1']['coeffs']),
            tuple(self.coeffs_low))
        self.assertTupleEqual(
            tuple(nasa_dict['polynomials']['polynomial2']['coeffs']),
            tuple(self.coeffs_high))
        self.assertEqual(
            nasa_dict['polynomials']['polynomial1']['Tmin']['value'],
            self.Tmin)
        self.assertEqual(
            nasa_dict['polynomials']['polynomial1']['Tmax']['value'],
            self.Tint)
        self.assertEqual(
            nasa_dict['polynomials']['polynomial2']['Tmin']['value'],
            self.Tint)
        self.assertEqual(
            nasa_dict['polynomials']['polynomial2']['Tmax']['value'],
            self.Tmax)

    def test_nasa_as_dict_minimal(self):
        """
        Test that NASA.as_dict does not contain empty, optional attributes
        """
        nasa_dict = NASA().as_dict()
        keys = nasa_dict.keys()
        self.assertNotIn('Tmin', keys)
        self.assertNotIn('Tmax', keys)
        self.assertNotIn('E0', keys)
        self.assertNotIn('Cp0', keys)
        self.assertNotIn('CpInf', keys)
        self.assertNotIn('label', keys)
        self.assertNotIn('comment', keys)