Source code for chempy.kinetics.tests.test_ode

# -*- coding: utf-8 -*-
from __future__ import (absolute_import, division, print_function)

try:
    import numpy as np
except ImportError:
    np = None

from chempy.arrhenius import ArrheniusParam
from chempy.chemistry import Substance, Reaction, ReactionSystem
from chempy.units import (
    SI_base_registry, get_derived_unit, allclose, units_library,
    to_unitless, default_units as u
)
from chempy.util._expr import Expr
from chempy.util.testing import requires
from .test_rates import _get_SpecialFraction_rsys
from ..rates import ArrheniusMassAction, Radiolytic
from .._rates import TPolyMassAction
from ..ode import get_odesys
from ..integrated import dimerization_irrev


@requires('numpy', 'pyodesys')
[docs]def test_get_odesys_1(): k = .2 a = Substance('A') b = Substance('B') r = Reaction({'A': 1}, {'B': 1}, param=k) rsys = ReactionSystem([r], [a, b]) odesys = get_odesys(rsys, include_params=True)[0] c0 = { 'A': 1.0, 'B': 3.0, } t = np.linspace(0.0, 10.0) xout, yout, info = odesys.integrate(t, rsys.as_per_substance_array(c0)) yref = np.zeros((t.size, 2)) yref[:, 0] = np.exp(-k*t) yref[:, 1] = 4 - np.exp(-k*t) assert np.allclose(yout, yref)
@requires('numpy', 'pyodesys')
[docs]def test_get_odesys_2(): g = Radiolytic([3.14]) a = Substance('A') b = Substance('B') r = Reaction({'A': 1}, {'B': 1}, param=g) rsys = ReactionSystem([r], [a, b]) odesys = get_odesys(rsys, include_params=True)[0] c0 = { 'A': 1.0, 'B': 3.0, } t = np.linspace(0.0, .1) xout, yout, info = odesys.integrate(t, rsys.as_per_substance_array(c0), {'doserate': 2.72, 'density': .998}) yref = np.zeros((t.size, 2)) k = 3.14*2.72*.998 yref[:, 0] = 1 - k*t yref[:, 1] = 3 + k*t assert np.allclose(yout, yref)
@requires(units_library, 'pyodesys')
[docs]def test_get_odesys_3(): M = u.molar s = u.second mol = u.mol m = u.metre substances = list(map(Substance, 'H2O H+ OH-'.split())) dissociation = Reaction({'H2O': 1}, {'H+': 1, 'OH-': 1}, 2.47e-5/s) recombination = Reaction({'H+': 1, 'OH-': 1}, {'H2O': 1}, 1.37e11/M/s) rsys = ReactionSystem([dissociation, recombination], substances) odesys = get_odesys( rsys, include_params=True, unit_registry=SI_base_registry, output_conc_unit=M)[0] c0 = {'H2O': 55.4*M, 'H+': 1e-7*M, 'OH-': 1e-4*mol/m**3} x, y, p = odesys.pre_process(-42*u.second, rsys.as_per_substance_array(c0, unit=M)) fout = odesys.f_cb(x, y, p) time_unit = get_derived_unit(SI_base_registry, 'time') conc_unit = get_derived_unit(SI_base_registry, 'concentration') r1 = to_unitless(55.4*2.47e-5*M/s, conc_unit/time_unit) r2 = to_unitless(1e-14*1.37e11*M/s, conc_unit/time_unit) assert abs(fout[0] - r2 + r1) < 1e-10 assert abs(fout[1] - r1 + r2) < 1e-10 assert abs(fout[2] - r1 + r2) < 1e-10
@requires(units_library, 'pyodesys')
[docs]def test_get_odesys__with_units(): a = Substance('A') b = Substance('B') molar = u.molar second = u.second r = Reaction({'A': 2}, {'B': 1}, param=1e-3/molar/second) rsys = ReactionSystem([r], [a, b]) odesys = get_odesys(rsys, include_params=True, unit_registry=SI_base_registry)[0] c0 = { 'A': 13*u.mol / u.metre**3, 'B': .2 * u.molar } conc_unit = get_derived_unit(SI_base_registry, 'concentration') t = np.linspace(0, 10)*u.hour xout, yout, info = odesys.integrate( t, rsys.as_per_substance_array(c0, unit=conc_unit), atol=1e-10, rtol=1e-12) t_unitless = to_unitless(xout, u.second) Aref = dimerization_irrev(t_unitless, 1e-6, 13.0) # Aref = 1/(1/13 + 2*1e-6*t_unitless) yref = np.zeros((xout.size, 2)) yref[:, 0] = Aref yref[:, 1] = 200 + (13-Aref)/2 print((yout - yref*conc_unit)/yout) assert allclose(yout, yref*conc_unit)
@requires('numpy', 'pyodesys')
[docs]def test_SpecialFraction(): k, kprime = 3.142, 2.718 rsys = _get_SpecialFraction_rsys(k, kprime) odesys = get_odesys(rsys, include_params=True)[0] c0 = {'H2': 13, 'Br2': 17, 'HBr': 19} r = k*c0['H2']*c0['Br2']**(3/2)/(c0['Br2'] + kprime*c0['HBr']) ref = rsys.as_per_substance_array({'H2': -r, 'Br2': -r, 'HBr': 2*r}) res = odesys.f_cb(0, rsys.as_per_substance_array(c0)) assert np.allclose(res, ref)
@requires(units_library, 'pyodesys')
[docs]def test_SpecialFraction_with_units(): k, kprime = 3.142 * u.s**-1 * u.molar**-0.5, 2.718 rsys = _get_SpecialFraction_rsys(k, kprime) odesys = get_odesys(rsys, include_params=True, unit_registry=SI_base_registry)[0] c0 = {'H2': 13*u.molar, 'Br2': 16*u.molar, 'HBr': 19*u.molar} r = k*c0['H2']*c0['Br2']**(3/2)/(c0['Br2'] + kprime*c0['HBr']) conc_unit = u.mol/u.metre**3 rate_unit = conc_unit/u.second ref = rsys.as_per_substance_array({'H2': -r, 'Br2': -r, 'HBr': 2*r}, unit=rate_unit) res = odesys.f_cb(0, rsys.as_per_substance_array(c0, unit=conc_unit)) assert allclose(to_unitless(ref, rate_unit), res)
@requires('pyodesys')
[docs]def test_ode_with_global_parameters(): ratex = ArrheniusMassAction([1e10, 40e3/8.3145]) rxn = Reaction({'A': 1}, {'B': 1}, ratex) rsys = ReactionSystem([rxn], 'A B') odesys = get_odesys(rsys, include_params=True)[0] conc = {'A': 3, 'B': 5} x, y, p = odesys.pre_process(-37, conc, {'temperature': 298.15}) fout = odesys.f_cb(x, y, p) ref = 3*1e10*np.exp(-40e3/8.3145/298.15) assert abs((fout[0] + ref)/ref) < 1e-14 assert abs((fout[1] - ref)/ref) < 1e-14
@requires('pyodesys')
[docs]def test_get_ode__ArrheniusParam(): rxn = Reaction({'A': 1}, {'B': 1}, None) rxn.param = ArrheniusParam(1e10, 40e3) rsys = ReactionSystem([rxn], 'A B') odesys = get_odesys(rsys, include_params=True)[0] conc = {'A': 3, 'B': 5} x, y, p = odesys.pre_process(-37, conc, {'temperature': 200}) fout = odesys.f_cb(x, y, p) ref = 3*1e10*np.exp(-40e3/8.314472/200) assert abs((fout[0] + ref)/ref) < 1e-14 assert abs((fout[1] - ref)/ref) < 1e-14
@requires('pyodesys')
[docs]def test_get_ode__Radiolytic(): rad = Radiolytic([2.4e-7]) rxn = Reaction({'A': 4, 'B': 1}, {'C': 3, 'D': 2}, rad) rsys = ReactionSystem([rxn], 'A B C D') odesys = get_odesys(rsys, include_params=True)[0] c = {'A': 3, 'B': 5, 'C': 11, 'D': 13} x, y, p = odesys.pre_process(-37, c, {'doserate': 0.4, 'density': 0.998}) fout = odesys.f_cb(x, y, p) r = 2.4e-7*0.4*0.998 ref = [-4*r, -r, 3*r, 2*r] assert np.all(abs((fout - ref)/ref) < 1e-14)
@requires('pyodesys', units_library)
[docs]def test_get_ode__Radiolytic__units(): rad = Radiolytic([2.4e-7*u.mol/u.joule]) rxn = Reaction({'A': 4, 'B': 1}, {'C': 3, 'D': 2}, rad) rsys = ReactionSystem([rxn], 'A B C D') odesys = get_odesys(rsys, include_params=True, unit_registry=SI_base_registry)[0] conc = {'A': 3*u.molar, 'B': 5*u.molar, 'C': 11*u.molar, 'D': 13*u.molar} x, y, p = odesys.pre_process(-37*u.second, conc, { 'doserate': 0.4*u.gray/u.second, 'density': 0.998*u.kg/u.decimetre**3 }) fout = odesys.f_cb(x, y, p) # f_cb does not carry any units r = 2.4e-7*0.4*0.998*1e3 # mol/m3 ref = [-4*r, -r, 3*r, 2*r] assert np.all(abs((fout - ref)/ref) < 1e-14)
[docs]class Density(Expr): """ Arguments: rho0 drhodT T0 """ parameter_keys = ('temperature',) kw = {} def __call__(self, variables, backend=None): rho0, drhodT, T0 = self.all_args(variables) return rho0 + drhodT*(variables['temperature'] - T0)
@requires('pyodesys')
[docs]def test_get_ode__Radiolytic__substitutions(): rad = Radiolytic([2.4e-7]) rxn = Reaction({'A': 4, 'B': 1}, {'C': 3, 'D': 2}, rad) rsys = ReactionSystem([rxn], 'A B C D') substance_rho = Density([1, -1e-3, 273.15]) odesys = get_odesys(rsys, include_params=True, substitutions={'density': substance_rho})[0] conc = {'A': 3, 'B': 5, 'C': 11, 'D': 13} state = {'doserate': 0.4, 'temperature': 298.15} x, y, p = odesys.pre_process(-37, conc, state) fout = odesys.f_cb(x, y, p) r = 2.4e-7*0.4*substance_rho({'temperature': 298.15}) ref = [-4*r, -r, 3*r, 2*r] assert np.all(abs((fout - ref)/ref) < 1e-14)
@requires('pyodesys', units_library)
[docs]def test_get_ode__Radiolytic__substitutions__units(): rad = Radiolytic([2.4e-7*u.mol/u.joule]) rxn = Reaction({'A': 4, 'B': 1}, {'C': 3, 'D': 2}, rad) rsys = ReactionSystem([rxn], 'A B C D') g_dm3 = u.gram / u.decimetre**3 kg_dm3 = u.kg / u.decimetre**3 substance_rho = Density([1*kg_dm3, -1*g_dm3/u.kelvin, 273.15*u.kelvin]) odesys = get_odesys(rsys, include_params=True, unit_registry=SI_base_registry, substitutions={'density': substance_rho})[0] conc = {'A': 3*u.molar, 'B': 5*u.molar, 'C': 11*u.molar, 'D': 13*u.molar} x, y, p = odesys.pre_process(-37*u.second, conc, {'doserate': 0.4*u.gray/u.second, 'temperature': 298.15*u.kelvin}) fout = odesys.f_cb(x, y, p) r = 2.4e-7*0.4*0.975 * 1e3 # mol/m3/s ref = [-4*r, -r, 3*r, 2*r] assert np.all(abs((fout - ref)/ref) < 1e-14)
@requires('pyodesys', units_library)
[docs]def test_get_ode__TPoly(): rate = TPolyMassAction([273.15*u.K, 10/u.molar/u.s, 2/u.molar/u.s/u.K]) rxn = Reaction({'A': 1, 'B': 1}, {'C': 3, 'D': 2}, rate, {'A': 3}) rsys = ReactionSystem([rxn], 'A B C D') odesys = get_odesys(rsys, unit_registry=SI_base_registry)[0] conc = {'A': 3*u.molar, 'B': 5*u.molar, 'C': 11*u.molar, 'D': 13*u.molar} x, y, p = odesys.pre_process(-37*u.second, conc, {'temperature': 298.15*u.kelvin}) fout = odesys.f_cb(x, y, p) r = 3*5*(10+2*25)*1000 # mol/m3/s ref = [-4*r, -r, 3*r, 2*r] assert np.all(abs((fout - ref)/ref) < 1e-14)