Fix proportional scaling to always scale to size 8 neighborhood

resolves #71

simulatingrisk/hawkdove/model.py

@@ -102,10 +102,15 @@ def num_dove_neighbors(self):
 
     @property
     def proportional_num_dove_neighbors(self):
-        """adjust the number of dove neighbors based on ratio between
-        play neighborhood and observed neighborhood, to scale observations
-        to the range of agent risk level."""
-        ratio = self.model.max_risk_level / self.model.observed_neighborhood
+        """adjust the number of dove neighbors to scale observations
+        to a standard range of risk levels."""
+        # for convenience and simplicity, we scale the neighborhood so
+        # that agent risk levels can always be defined as 0-9 no matter
+        # the neighborhood size. (Can also be thought of as always
+        # scaling to a neighborhood size of 8.).
+        # Agent risk levels are 0-9 but scaling is 1-8, since 0 and 9
+        # always play hawk and dove respectively.
+        ratio = 8 / self.model.observed_neighborhood
         # always round to an integer
         return round(ratio * self.num_dove_neighbors)
 

tests/test_hawkdove.py

@@ -197,19 +197,31 @@ def test_proportional_num_dove_neighbors():
     model = HawkDoveSingleRiskModel(4, agent_risk_level=3)
     agent = HawkDoveSingleRiskAgent(1, model)
 
-    ## equal play/observed; scales to 9 (risk level range)
+    ## equal play/observed; scales to 8 (risk level range)
     model.observed_neighborhood = 4
+    with patch.object(HawkDoveAgent, "num_dove_neighbors", 4):
+        assert agent.proportional_num_dove_neighbors == 8
     with patch.object(HawkDoveAgent, "num_dove_neighbors", 3):
-        assert agent.proportional_num_dove_neighbors == 7
+        assert agent.proportional_num_dove_neighbors == 6
+    with patch.object(HawkDoveAgent, "num_dove_neighbors", 2):
+        assert agent.proportional_num_dove_neighbors == 4
 
     model.observed_neighborhood = 8
     with patch.object(HawkDoveAgent, "num_dove_neighbors", 5):
+        assert agent.proportional_num_dove_neighbors == 5
+    with patch.object(HawkDoveAgent, "num_dove_neighbors", 6):
         assert agent.proportional_num_dove_neighbors == 6
+    with patch.object(HawkDoveAgent, "num_dove_neighbors", 7):
+        assert agent.proportional_num_dove_neighbors == 7
 
     # observe more than 8
     model.observed_neighborhood = 24
     with patch.object(HawkDoveAgent, "num_dove_neighbors", 20):
+        assert agent.proportional_num_dove_neighbors == 7
+    with patch.object(HawkDoveAgent, "num_dove_neighbors", 23):
         assert agent.proportional_num_dove_neighbors == 8
+    with patch.object(HawkDoveAgent, "num_dove_neighbors", 6):
+        assert agent.proportional_num_dove_neighbors == 2
 
 
 def test_agent_choose_when_observe_play_differ():