Added functions to python interface

feos-org · prehner · Apr 6, 2022 · Feb 25, 2022 · Mar 14, 2022 · Mar 22, 2022
commit 0f8ae0216797377d23dba2b8e68387ba2a61ffd0
diff --git a/src/python/state.rs b/src/python/state.rs
@@ -525,6 +525,29 @@ macro_rules! impl_state {
                 self.0.ln_phi().view().to_pyarray(py)
             }
 
+            /// Return logarithmic pure substance fugacity coefficient.
+            /// 
+            /// For each component, the hypothetical liquid fugacity coefficient
+            /// at mixture temperature and pressure is computed.
+            /// 
+            /// Returns
+            /// -------
+            /// numpy.ndarray
+            #[pyo3(text_signature = "($self)")]
+            fn ln_phi_pure<'py>(&self, py: Python<'py>) -> PyResult<&'py PyArray1<f64>> {
+                Ok(self.0.ln_phi_pure()?.view().to_pyarray(py))
+            }
+
+            /// Return logarithmic symmetric activity coefficient.
+            /// 
+            /// Returns
+            /// -------
+            /// numpy.ndarray
+            #[pyo3(text_signature = "($self)")]
+            fn ln_symmetric_activity_coefficient<'py>(&self, py: Python<'py>) -> PyResult<&'py PyArray1<f64>> {
+                Ok(self.0.ln_symmetric_activity_coefficient()?.view().to_pyarray(py))
+            }
+
             /// Return derivative of logarithmic fugacity coefficient w.r.t. temperature.
             ///
             /// Returns

diff --git a/src/state/properties.rs b/src/state/properties.rs
@@ -314,11 +314,19 @@ impl<U: EosUnit, E: EquationOfState> State<U, E> {
                     &(arr1(&[1.0]) * U::reference_moles()),
                     crate::DensityInitialization::Liquid,
                 )?;
-                state.ln_phi()[0]
+                Ok(state.ln_phi()[0])
             })
             .collect()
     }
 
+    /// Activity coefficient $\ln \gamma_i = \ln \varphi_i(T, p, \mathbf{N}) - \ln \varphi_i(T, p)$
+    pub fn ln_symmetric_activity_coefficient(&self) -> EosResult<Array1<f64>> {
+        match self.eos.components() {
+            1 => Ok(arr1(&[0.0])),
+            _ => Ok(self.ln_phi() - &self.ln_phi_pure()?),
+        }
+    }
+
     /// Partial derivative of the logarithm of the fugacity coefficient w.r.t. temperature: $\left(\frac{\partial\ln\varphi_i}{\partial T}\right)_{p,N_i}$
     pub fn dln_phi_dt(&self) -> QuantityArray1<U> {
         let func = |s: &Self, evaluate: Evaluate| {
@@ -490,11 +498,6 @@ impl<U: EosUnit, E: EquationOfState> State<U, E> {
             .unwrap()
     }
 
-    /// Activity coefficient $\ln \gamma_i = \ln \varphi_i(T, p, \mathbf{N}) - \ln \varphi_i(T, p)$
-    pub fn ln_symmetric_activity_coefficient(&self) -> Array1<f64> {
-        self.ln_phi() - self.ln_phi_pure()
-    }
-
     /// Helmholtz energy $A$ evaluated for each contribution of the equation of state.
     pub fn helmholtz_energy_contributions(&self) -> Vec<(String, QuantityScalar<U>)> {
         let new_state = self.derive0();