refactor: Use Mesa 2.2 API for Trading Sugarscape

examples/sugarscape_g1mt/sugarscape_g1mt/model.py

@@ -68,22 +68,17 @@ def __init__(
         self.enable_trade = enable_trade
         self.running = True
 
-        # initiate activation schedule
-        self.schedule = mesa.time.RandomActivationByType(self)
         # initiate mesa grid class
         self.grid = mesa.space.MultiGrid(self.width, self.height, torus=False)
         # initiate datacollector
         self.datacollector = mesa.DataCollector(
             model_reporters={
-                "Trader": lambda m: m.schedule.get_type_count(Trader),
+                "Trader": lambda m: len(m.get_agents_of_type(Trader)),
                 "Trade Volume": lambda m: sum(
-                    len(a.trade_partners)
-                    for a in m.schedule.agents_by_type[Trader].values()
+                    len(a.trade_partners) for a in m.get_agents_of_type(Trader)
                 ),
                 "Price": lambda m: geometric_mean(
-                    flatten(
-                        [a.prices for a in m.schedule.agents_by_type[Trader].values()]
-                    )
+                    flatten([a.prices for a in m.get_agents_of_type(Trader)])
                 ),
             },
             agent_reporters={"Trade Network": lambda a: get_trade(a)},
@@ -98,7 +93,6 @@ def __init__(
             max_sugar = sugar_distribution[x, y]
             max_spice = spice_distribution[x, y]
             resource = Resource(agent_id, self, (x, y), max_sugar, max_spice)
-            self.schedule.add(resource)
             self.grid.place_agent(resource, (x, y))
             agent_id += 1
 
@@ -133,34 +127,21 @@ def __init__(
             )
             # place agent
             self.grid.place_agent(trader, (x, y))
-            self.schedule.add(trader)
             agent_id += 1
 
-    def randomize_traders(self):
-        """
-        helper function for self.step()
-
-        puts traders in randomized list for step function
-        """
-
-        traders_shuffle = list(self.schedule.agents_by_type[Trader].values())
-        self.random.shuffle(traders_shuffle)
-
-        return traders_shuffle
-
     def step(self):
         """
         Unique step function that does staged activation of sugar and spice
         and then randomly activates traders
         """
         # step Resource agents
-        for resource in self.schedule.agents_by_type[Resource].values():
+        for resource in self.get_agents_of_type(Resource):
             resource.step()
 
         # step trader agents
         # to account for agent death and removal we need a seperate data strcuture to
         # iterate
-        trader_shuffle = self.randomize_traders()
+        trader_shuffle = self.get_agents_of_type(Trader).shuffle(inplace=True)
 
         for agent in trader_shuffle:
             agent.prices = []
@@ -175,10 +156,7 @@ def step(self):
             self.datacollector.collect(self)
             return
 
-        trader_shuffle = self.randomize_traders()
-
-        for agent in trader_shuffle:
-            agent.trade_with_neighbors()
+        self.get_agents_of_type(Trader).shuffle(inplace=True).do("trade_with_neighbors")
 
         self._steps += 1
         # collect model level data

examples/sugarscape_g1mt/sugarscape_g1mt/server.py

@@ -1,7 +1,7 @@
 import mesa
 
 from .model import SugarscapeG1mt
-from .resource_agents import Spice, Sugar
+from .resource_agents import Resource
 from .trader_agents import Trader
 
 sugar_dic = {4: "#005C00", 3: "#008300", 2: "#00AA00", 1: "#00F800"}
@@ -21,9 +21,18 @@ def Agent_portrayal(agent):
             "Color": "#FF0A01",
         }
 
-    elif isinstance(agent, Sugar):
-        color = sugar_dic[agent.amount] if agent.amount != 0 else "#D6F5D6"
-        layer = 1 if agent.amount > 2 else 0
+    elif isinstance(agent, Resource):
+        resource_type = "sugar" if agent.max_sugar > agent.max_spice else "spice"
+        if resource_type == "sugar":
+            color = (
+                sugar_dic[agent.sugar_amount] if agent.sugar_amount != 0 else "#D6F5D6"
+            )
+            layer = 1 if agent.sugar_amount > 2 else 0
+        else:
+            color = (
+                spice_dic[agent.spice_amount] if agent.spice_amount != 0 else "#D6F5D6"
+            )
+            layer = 1 if agent.spice_amount > 2 else 0
         return {
             "Color": color,
             "Shape": "rect",
@@ -33,18 +42,6 @@ def Agent_portrayal(agent):
             "h": 1,
         }
 
-    elif isinstance(agent, Spice):
-        color = spice_dic[agent.amount] if agent.amount != 0 else "#D6F5D6"
-        layer = 1 if agent.amount > 2 else 0
-        return {
-            "Color": color,
-            "Shape": "rect",
-            "Filled": "true",
-            "Layer": 0,
-            "w": 1,
-            "h": 1,
-        }
-
     return {}
 
 

examples/sugarscape_g1mt/sugarscape_g1mt/trader_agents.py

@@ -306,7 +306,7 @@ def maybe_die(self):
 
         if self.is_starved():
             self.model.grid.remove_agent(self)
-            self.model.schedule.remove(self)
+            self.remove()
 
     def trade_with_neighbors(self):
         """

examples/sugarscape_g1mt/tests.py

@@ -23,7 +23,7 @@ def test_decreasing_price_variance():
     model.datacollector._new_model_reporter(
         "price_variance",
         lambda m: np.var(
-            flatten([a.prices for a in m.schedule.agents_by_type[Trader].values()])
+            flatten([a.prices for a in m.get_agents_of_type(Trader)])
         ),
     )
     model.run_model(step_count=50)
@@ -40,7 +40,7 @@ def calculate_carrying_capacities(enable_trade):
         for vision_max in visions:
             model = SugarscapeG1mt(vision_max=vision_max, enable_trade=enable_trade)
             model.run_model(step_count=50)
-            carrying_capacities.append(len(model.schedule.agents_by_type[Trader]))
+            carrying_capacities.append(len(model.get_agents_of_type(Trader)))
         return carrying_capacities
 
     # Carrying capacity should increase over mean vision (figure IV-6).