Removed documentation for pr; changed VolumeGas to use EOS

docs/thermo.rst

@@ -27,7 +27,6 @@ Submodules
    thermo.miscdata
    thermo.permittivity
    thermo.phase_change
-   thermo.pr
    thermo.reaction
    thermo.refractivity
    thermo.safety

tests/test_eos.py

@@ -814,9 +814,7 @@ def dV_dT(T, P, eos, order=0, phase=True, Tc=507.6, Pc=3025000., omega=0.2975):
                             continue
                         x.append(numer)
                         y.append(ana)
-    ans = allclose_variable(x, y, limits=[.009, .05, .65, .93],rtols=[1E-5, 1E-6, 1E-9, 1E-10])
-    if not ans:
-        raise Exception('dVdT numerical derivative failing!')
+    assert allclose_variable(x, y, limits=[.009, .05, .65, .93],rtols=[1E-5, 1E-6, 1E-9, 1E-10])
 
 
 @pytest.mark.slow
@@ -850,8 +848,6 @@ def dV_dP(P, T, eos, order=0, phase=True, Tc=507.6, Pc=3025000., omega=0.2975):
                             continue
                         x.append(numer)
                         y.append(ana)
-    ans = allclose_variable(x, y, limits=[.02, .04, .04, .05, .15, .45, .95],
+    assert allclose_variable(x, y, limits=[.02, .04, .04, .05, .15, .45, .95],
                             rtols=[1E-2, 1E-3, 1E-4, 1E-5, 1E-6, 1E-7, 1E-9])
-    if not ans:
-        raise Exception('Error')
 

tests/test_utils.py

@@ -445,14 +445,10 @@ def test_allclose_variable():
     x = [2.7244322249597719e-08, 3.0105683900110473e-10, 2.7244124924802327e-08, 3.0105259397637556e-10, 2.7243929226310193e-08, 3.0104990272770901e-10, 2.7243666849384451e-08, 3.0104101821236015e-10, 2.7243433745917367e-08, 3.0103707421519949e-10]
     y = [2.7244328304561904e-08, 3.0105753470546008e-10, 2.724412872417824e-08,  3.0105303055834564e-10, 2.7243914341030203e-08, 3.0104819238021998e-10, 2.7243684057561379e-08, 3.0104299541023674e-10, 2.7243436694839306e-08, 3.010374130526363e-10]
 
-    ans = allclose_variable(x, y, limits=[.0, .5], rtols=[1E-5, 1E-6])
-    if not ans:
-        raise Exception('Failure')
+    assert allclose_variable(x, y, limits=[.0, .5], rtols=[1E-5, 1E-6])
 
     with pytest.raises(Exception):
-        ans = allclose_variable(x, y, limits=[.0, .1], rtols=[1E-5, 1E-6])
-        if not ans:
-            raise Exception('Failure')
+        assert allclose_variable(x, y, limits=[.0, .1], rtols=[1E-5, 1E-6])
 
     with pytest.raises(Exception):
         allclose_variable(x, y[1:], limits=[.0, .5], rtols=[1E-5, 1E-6])
@@ -463,6 +459,8 @@ def test_allclose_variable():
 
     x = [1,1,1,1,1,1,1,1,1]
     y = [.9,.9,.9,.9,.9,.9,.9,.9, .9]
-    ans = allclose_variable(x, y, limits=[.0], atols=[.1])
-    if ans is False:
-        raise Exception('Failure on a unit test')
+    assert allclose_variable(x, y, limits=[.0], atols=[.1])
+
+
+def test_horner():
+    assert horner([1,2,3], 3) == 18

tests/test_volume.py

@@ -25,6 +25,7 @@
 import pytest
 import pandas as pd
 from thermo.volume import *
+from thermo.eos import *
 from thermo.utils import Vm_to_rho
 from thermo.identifiers import checkCAS
 
@@ -270,9 +271,10 @@ def test_ideal_gas():
 
 @pytest.mark.meta_T_dept
 def test_VolumeGas():
-    SO2 = VolumeGas(CASRN='7446-09-5', MW=64.0638,  Tc=430.8, Pc=7884098.25, omega=0.251, dipole=1.63)
+    eos = [PR(T=300, P=1E5, Tc=430.8, Pc=7884098.25, omega=0.251)]
+    SO2 = VolumeGas(CASRN='7446-09-5', MW=64.0638,  Tc=430.8, Pc=7884098.25, omega=0.251, dipole=1.63, eos=eos)
     Vm_calcs = [(SO2.set_user_methods_P(i, forced_P=True), SO2.TP_dependent_property(305, 1E5))[1] for i in SO2.all_methods_P]
-    Vm_exp = [0.025024421772080314, 0.02499978619699621, 0.02499586901117375, 0.02499627309459868, 0.02499978619699621, 0.024971467450477493, 0.02535910239]
+    Vm_exp = [0.025024302563892417, 0.02499978619699621, 0.02499586901117375, 0.02499627309459868, 0.02499978619699621, 0.024971467450477493, 0.02535910239]
     assert_allclose(sorted(Vm_calcs), sorted(Vm_exp))
 
     # Test that methods return None

thermo/chemical.py

@@ -321,33 +321,39 @@ def set_eos(self, T, P, eos=PR):
             self.eos = eos(T=T, P=P, Tc=self.Tc, Pc=self.Pc, omega=self.omega)
         else:
             self.eos = GCEOS_DUMMY(T=T, P=P)
+    @property
+    def eos(self):
+        return self.eos_in_a_box[0]
+    @eos.setter
+    def eos(self, eos):
         if self.eos_in_a_box:
             self.eos_in_a_box.pop()
         # Pass this mutable list to objects so if it is changed, it gets 
         # changed in the property method too
-        self.eos_in_a_box.append(self.eos) 
+        self.eos_in_a_box.append(eos) 
+
 
     def set_TP_sources(self):
         # Tempearture and Pressure Denepdence
         # Get and choose initial methods
-        self.VaporPressure = VaporPressure(Tb=self.Tb, Tc=self.Tc, Pc=self.Pc, omega=self.omega, CASRN=self.CAS, eos=self.eos_in_a_box)
+        self.VaporPressure = VaporPressure(Tb=self.Tb, Tc=self.Tc, Pc=self.Pc, 
+                                           omega=self.omega, CASRN=self.CAS, 
+                                           eos=self.eos_in_a_box)
         self.Psat_298 = self.VaporPressure.T_dependent_property(298.15)
 
-
         self.VolumeLiquid = VolumeLiquid(MW=self.MW, Tb=self.Tb, Tc=self.Tc,
                           Pc=self.Pc, Vc=self.Vc, Zc=self.Zc, omega=self.omega,
-                          dipole=self.dipole, Psat=self.VaporPressure.T_dependent_property, CASRN=self.CAS)
+                          dipole=self.dipole, 
+                          Psat=self.VaporPressure.T_dependent_property, 
+                          eos=self.eos_in_a_box, CASRN=self.CAS)
 
         self.Vml_Tb = self.VolumeLiquid.T_dependent_property(self.Tb) if self.Tb else None
         self.Vml_Tm = self.VolumeLiquid.T_dependent_property(self.Tm) if self.Tm else None
         self.Vml_STP = self.VolumeLiquid.T_dependent_property(298.15)
 
-        # set molecular_diameter; depends on Vml_Tb, Vml_Tm
-        self.molecular_diameter_sources = molecular_diameter(Tc=self.Tc, Pc=self.Pc, Vc=self.Vc, Zc=self.Zc, omega=self.omega, Vm=self.Vml_Tm, Vb=self.Vml_Tb, AvailableMethods=True, CASRN=self.CAS)
-        self.molecular_diameter_source = self.molecular_diameter_sources[0]
-        self.molecular_diameter = molecular_diameter(Tc=self.Tc, Pc=self.Pc, Vc=self.Vc, Zc=self.Zc, omega=self.omega, Vm=self.Vml_Tm, Vb=self.Vml_Tb, Method=self.molecular_diameter_source, CASRN=self.CAS)
-
-        self.VolumeGas = VolumeGas(MW=self.MW, Tc=self.Tc, Pc=self.Pc, omega=self.omega, dipole=self.dipole, CASRN=self.CAS)
+        self.VolumeGas = VolumeGas(MW=self.MW, Tc=self.Tc, Pc=self.Pc, 
+                                   omega=self.omega, dipole=self.dipole, 
+                                   eos=self.eos_in_a_box, CASRN=self.CAS)
 
         self.VolumeSolid = VolumeSolid(CASRN=self.CAS, MW=self.MW, Tt=self.Tt)
 
@@ -383,8 +389,14 @@ def set_TP_sources(self):
 
         self.phase_STP = identify_phase(T=298.15, P=101325., Tm=self.Tm, Tb=self.Tb, Tc=self.Tc, Psat=self.Psat_298)
 
+        # set molecular_diameter; depends on Vml_Tb, Vml_Tm
+        self.molecular_diameter_sources = molecular_diameter(Tc=self.Tc, Pc=self.Pc, Vc=self.Vc, Zc=self.Zc, omega=self.omega, Vm=self.Vml_Tm, Vb=self.Vml_Tb, AvailableMethods=True, CASRN=self.CAS)
+        self.molecular_diameter_source = self.molecular_diameter_sources[0]
+        self.molecular_diameter = molecular_diameter(Tc=self.Tc, Pc=self.Pc, Vc=self.Vc, Zc=self.Zc, omega=self.omega, Vm=self.Vml_Tm, Vb=self.Vml_Tb, Method=self.molecular_diameter_source, CASRN=self.CAS)
+
     def set_TP(self):
-        self.eos.to_TP(T=self.T, P=self.P)
+        self.eos = self.eos.to_TP(T=self.T, P=self.P)
+        self.eos_in_a_box[0] = self.eos
         self.Psat = self.VaporPressure.T_dependent_property(T=self.T)
 
         self.Vms = self.VolumeSolid.T_dependent_property(T=self.T)

thermo/eos.py

@@ -92,6 +92,7 @@ class GCEOS(object):
     the liquid or gas phase with the convention of adding on `_l` or `_g` to
     the variable names.
     '''
+    kwargs = {}
     def check_sufficient_inputs(self):
         '''Method to an exception if none of the pairs (T, P), (T, V), or 
         (P, V) are given. '''
@@ -643,6 +644,23 @@ def Psat(self, T, polish=False):
         -------
         Psat : float
             Vapor pressure, [Pa]
+            
+        Notes
+        -----
+        Equations of state derived from another but using the same form and 
+        `a` and `b` values work with the former's coefficients.
+        
+        All coefficients were derived with numpy's polyfit. The intersection
+        between the polynomials is continuous, but there is a step change
+        in its derivative.
+        
+        Form for the regression is inspired from [1]_.
+                    
+        References
+        ----------
+        .. [1] Soave, G. "Direct Calculation of Pure-Compound Vapour Pressures 
+           through Cubic Equations of State." Fluid Phase Equilibria 31, no. 2 
+           (January 1, 1986): 203-7. doi:10.1016/0378-3812(86)90013-0. 
         '''
         alpha = self.a_alpha_and_derivatives(T, full=False)/self.a
         Tr = T/self.Tc
@@ -664,7 +682,10 @@ def to_solve(P):
 
     def to_TP(self, T, P):
         if T != self.T or P != self.P:
-            self.__init__(T=T, P=P, Tc=self.Tc, Pc=self.Pc, omega=self.omega)
+            return self.__class__(T=T, P=P, Tc=self.Tc, Pc=self.Pc, omega=self.omega, **self.kwargs)
+        else:
+            return self
+
 
 class GCEOS_DUMMY(GCEOS):
     def __init__(self, T=None, P=None, **kwargs):
@@ -1694,6 +1715,7 @@ def __init__(self, Tc, Pc, omega, T=None, P=None, V=None, kappa1=0):
         self.T = T
         self.P = P
         self.V = V
+        self.kwargs = {'kappa1': kappa1}
 
         self.a = self.c1*R*R*Tc*Tc/Pc
         self.b = self.c2*R*Tc/Pc
@@ -1890,6 +1912,7 @@ def __init__(self, Tc, Pc, omega, T=None, P=None, V=None, kappa1=0, kappa2=0, ka
         self.P = P
         self.V = V
         self.check_sufficient_inputs()
+        self.kwargs = {'kappa1': kappa1, 'kappa2': kappa2, 'kappa3': kappa3}
 
         self.a = self.c1*R*R*Tc*Tc/Pc
         self.b = self.c2*R*Tc/Pc
@@ -2576,6 +2599,7 @@ def __init__(self, Tc, Pc, omega=None, T=None, P=None, V=None, S1=None, S2=0):
         self.T = T
         self.P = P
         self.V = V
+        self.kwargs = {'S1': S1, 'S2': S2}
         self.check_sufficient_inputs()
 
         if S1 is None and omega is None:

thermo/pr.py

@@ -27,6 +27,10 @@
 from scipy.optimize import fsolve
 from numpy import roots
 from thermo.utils import log, exp
+'''
+THIS FILE IS EXTREMELY DEPRECATED! CURRENTLY ONLY USED FOR THE CASE OF GAS 
+MIXTURE VOLUMES.
+'''
 
 R = 8.3145
 

thermo/utils.py

@@ -32,7 +32,7 @@
 'Z_from_virial_pressure_form', 'zs_to_ws', 'ws_to_zs', 'zs_to_Vfs', 
 'Vfs_to_zs', 'none_and_length_check', 'normalize', 'mixing_simple', 
 'mixing_logarithmic', 'phase_set_property', 'TDependentProperty', 
-'TPDependentProperty', 'allclose_variable']
+'TPDependentProperty', 'allclose_variable', 'horner']
 
 from cmath import sqrt as csqrt
 import numpy as np

thermo/vapor_pressure.py

@@ -180,7 +180,7 @@ def TRC_Antoine_extended(T, Tc, to, A, B, C, n, E, F):
 
 vapor_pressure_methods = [WAGNER_MCGARRY, WAGNER_POLING, ANTOINE_EXTENDED_POLING,
                           COOLPROP, ANTOINE_POLING, VDI_TABULAR, AMBROSE_WALTON,
-                          LEE_KESLER_PSAT, BOILING_CRITICAL, SANJARI]
+                          LEE_KESLER_PSAT, EOS, BOILING_CRITICAL, SANJARI]
 '''Holds all methods available for the VaporPressure class, for use in
 iterating over them.'''
 
@@ -292,7 +292,7 @@ class VaporPressure(TDependentProperty):
 
     ranked_methods = [WAGNER_MCGARRY, WAGNER_POLING, ANTOINE_EXTENDED_POLING,
                       COOLPROP, ANTOINE_POLING, VDI_TABULAR, AMBROSE_WALTON,
-                      LEE_KESLER_PSAT, BOILING_CRITICAL, SANJARI]
+                      LEE_KESLER_PSAT, BOILING_CRITICAL, EOS, SANJARI]
     '''Default rankings of the available methods.'''
 
     def __init__(self, Tb=None, Tc=None, Pc=None, omega=None, CASRN='', 
@@ -393,6 +393,8 @@ def load_all_methods(self):
             methods.append(LEE_KESLER_PSAT)
             methods.append(AMBROSE_WALTON)
             methods.append(SANJARI)
+            if self.eos:
+                methods.append(EOS)
             Tmins.append(0.01); Tmaxs.append(self.Tc)
         self.all_methods = set(methods)
         if Tmins and Tmaxs:
@@ -440,6 +442,8 @@ def calculate(self, T, method):
             Psat = Ambrose_Walton(T, self.Tc, self.Pc, self.omega)
         elif method == SANJARI:
             Psat = Sanjari(T, self.Tc, self.Pc, self.omega)
+        elif method == EOS:
+            Psat = self.eos[0].Psat(T)
         elif method in self.tabular_data:
             Psat = self.interpolate(T, method)
         return Psat
@@ -482,7 +486,7 @@ def test_method_validity(self, T, method):
         elif method == COOLPROP:
             if T < self.CP_f.Tmin or T < self.CP_f.Tt or T > self.CP_f.Tmax or T > self.CP_f.Tc:
                 return False
-        elif method in [BOILING_CRITICAL, LEE_KESLER_PSAT, AMBROSE_WALTON, SANJARI]:
+        elif method in [BOILING_CRITICAL, LEE_KESLER_PSAT, AMBROSE_WALTON, SANJARI, EOS]:
             if T > self.Tc or T < 0:
                 return False
             # No lower limit