Added ADD method to the Baryakhtar code (not optimal but working for now, we could move this function to the helpers). Made CHI parameter a property so it is updated properly when this driver parameter is called and defined

Author: davidcortesortuno

fidimag/micro/baryakhtar.py

@@ -24,12 +24,30 @@ def __init__(self, mesh, spin, Ms, field, pins,
                                         use_jac=use_jac
                                         )
 
-        self.chi = chi
+        self._chi = 1e-3
+        add(Relaxation(self.chi, name='chi_relax'),
+            self.interactions, self.data_saver,
+            self.mesh, self.spin, self._Ms)
+
         self.lap = Laplace(mesh)
-        self.add(Relaxation(chi))
+        # OLD: self.add(Relaxation(chi))
 
         self.beta = 0
 
+    def get_chi(self):
+        """
+        """
+        return self._chi
+
+    def set_chi(self, chi):
+        """
+        """
+        for i in self.interactions:
+            if i.name == 'chi_relax':
+                i.chi = chi
+
+    chi = property(get_chi, set_chi)
+
     def sundials_rhs(self, t, y, ydot):
 
         self.t = t
@@ -107,3 +125,54 @@ def sundials_rhs(self, t, y, ydot):
         #ydot[:] = self.dm_dt[:]
 
         return 0
+
+
+def add(interaction, interactions_list, data_saver,
+        mesh, spin, magnetisation, save_field=False):
+
+    """
+
+    Add an interaction to the interaction list.
+    This function is based on the Sim class *add* method
+    (it is likely that this function will be moved to the common
+     helpers in the future)
+
+    OPTIONAL ARGUMENTS:
+
+    save_field      :: Set True to save the average values of this
+                       interaction field when relaxing the system
+
+    """
+
+    # magnetisation is Ms for the micromagnetic Sim class, and it is
+    # mu_s for the atomistic Sim class
+    interaction.setup(mesh, spin, magnetisation)
+
+    # TODO: FIX  --> ??
+    # When adding an interaction that was previously added, using
+    # the same name, append a '_2' to the new interaction name (?)
+    for i in interactions_list:
+        if i.name == interaction.name:
+            interaction.name = i.name + '_2'
+
+    interactions_list.append(interaction)
+
+    # Specify a name for the energy of the interaction, which will
+    # appear in a file with saved values
+    # When saving the energy values, we call the compute_energy() method
+    # from the (micromagnetic/atomistic) Energy class (overhead?)
+    energy_name = 'E_{0}'.format(interaction.name)
+    data_saver.entities[energy_name] = {
+        'unit': '<J>',
+        'get': lambda sim: sim.get_interaction(interaction.name).compute_energy(),
+        'header': energy_name}
+
+    # Save the average values of the interaction vector field components
+    if save_field:
+        fn = '{0}'.format(interaction.name)
+        data_saver.entities[fn] = {
+            'unit': '<>',
+            'get': lambda sim: sim.get_interaction(interaction.name).average_field(),
+            'header': ('%s_x' % fn, '%s_y' % fn, '%s_z' % fn)}
+
+    data_saver.update_entity_order()