expose additive kernel coefficient property in Python

src/env_state.F90

@@ -94,6 +94,28 @@ subroutine f_env_state_get_height(ptr_c, height) bind(C)
 
     end subroutine
 
+    subroutine f_env_state_set_additive_kernel_coefficient(ptr_c, additive_kernel_coefficient) bind(C)
+        type(env_state_t), pointer :: ptr_f => null()
+        type(c_ptr), intent(in) :: ptr_c
+        real(c_double), intent(in) :: additive_kernel_coefficient
+
+        call c_f_pointer(ptr_c, ptr_f)
+
+        ptr_f%additive_kernel_coefficient = additive_kernel_coefficient
+
+    end subroutine
+
+    subroutine f_env_state_get_additive_kernel_coefficient(ptr_c, additive_kernel_coefficient) bind(C)
+        type(env_state_t), pointer :: ptr_f => null()
+        type(c_ptr), intent(in) :: ptr_c
+        real(c_double), intent(out) :: additive_kernel_coefficient
+
+        call c_f_pointer(ptr_c, ptr_f)
+
+        additive_kernel_coefficient = ptr_f%additive_kernel_coefficient
+
+    end subroutine
+
     subroutine f_env_state_set_pressure(ptr_c, pressure) bind(C)
         type(env_state_t), pointer :: ptr_f => null()
         type(c_ptr), intent(in) :: ptr_c

src/env_state.hpp

@@ -14,6 +14,8 @@ extern "C" void f_env_state_dtor(void *ptr) noexcept;
 extern "C" void f_env_state_from_json(const void *ptr) noexcept;
 extern "C" void f_env_state_set_temperature(const void *ptr, const double *temperature) noexcept;
 extern "C" void f_env_state_get_temperature(const void *ptr, double *temperature) noexcept;
+extern "C" void f_env_state_set_additive_kernel_coefficient(const void *ptr, const double *additive_kernel_coefficient) noexcept;
+extern "C" void f_env_state_get_additive_kernel_coefficient(const void *ptr, double *additive_kernel_coefficient) noexcept;
 extern "C" void f_env_state_get_rel_humid(const void *ptr, double *rel_humid) noexcept;
 extern "C" void f_env_state_set_height(const void *ptr, const double *height) noexcept;
 extern "C" void f_env_state_get_height(const void *ptr, double *height) noexcept;
@@ -82,6 +84,23 @@ struct EnvState {
         return height;
     }
 
+    static void set_additive_kernel_coefficient(const EnvState &self, const double additive_kernel_coefficient) {
+        f_env_state_set_additive_kernel_coefficient(
+            self.ptr.f_arg(),
+            &additive_kernel_coefficient
+        );
+    }
+
+    static auto get_additive_kernel_coefficient(const EnvState &self) {
+        double additive_kernel_coefficient;
+
+        f_env_state_get_additive_kernel_coefficient(
+            self.ptr.f_arg(),
+            &additive_kernel_coefficient
+        );
+        return additive_kernel_coefficient;
+    }
+
     static void set_pressure(const EnvState &self, const double pressure) {
         f_env_state_set_pressure(
             self.ptr.f_arg(),

src/pypartmc.cpp

@@ -324,6 +324,8 @@ PYBIND11_MODULE(_PyPartMC, m) {
             "Ambient pressure (Pa)")
         .def_property_readonly("air_density", &EnvState::air_density,
             "Air density (kg m^{-3})")
+        .def_property("additive_kernel_coefficient", &EnvState::get_additive_kernel_coefficient, &EnvState::set_additive_kernel_coefficient,
+            "Scaling coefficient for additive coagulation kernel.")
     ;
 
     py::class_<Photolysis>(m,

tests/test_env_state.py

@@ -72,6 +72,18 @@ def test_pressure():
         # assert
         assert value == sut.pressure
 
+    @staticmethod
+    def test_additive_kernel_coefficient():
+        # arrange
+        sut = ppmc.EnvState(ENV_STATE_CTOR_ARG_MINIMAL)
+        value = 1500.0
+
+        # act
+        sut.additive_kernel_coefficient = value
+
+        # assert
+        assert value == sut.additive_kernel_coefficient
+
     @staticmethod
     def test_humidity_ctor():
         # arrange and act