WIP: stochastic hill climber

experiments/stochastic_hillclimber/actors/scape.py

@@ -0,0 +1,58 @@
+# actors/scape.py
+from actor import Actor
+import math
+
+
+class XorScape(Actor):
+    def __init__(self):
+        super().__init__("XorScape")
+        self.data = [
+            ([-1, -1], [-1]),
+            ([1, -1], [1]),
+            ([-1, 1], [1]),
+            ([1, 1], [-1])
+        ]
+        self.index = 0
+        self.error_acc = 0.0
+        self.last_actuator = None  # <-- wer uns zuletzt "action" geschickt hat
+
+    async def run(self):
+        while True:
+            msg = await self.inbox.get()
+            tag = msg[0]
+
+            if tag == "sense":
+                print("SCAPE: got sensed by sensor...")
+                # Sensor fragt nach Input
+                _, sid, from_pid = msg
+                self.last_actuator = from_pid  # merken, wer beteiligt ist
+                inputs, correct = self.data[self.index]
+                print("SENSOR input /correct: ", inputs, correct)
+                await from_pid.send(("percept", inputs))
+
+            elif tag == "action":
+                _, output, from_pid = msg
+                _, correct = self.data[self.index]
+
+                # Calculate RMSE like the Erlang version
+                step_error = sum((o - c) ** 2 for o, c in zip(output, correct))
+                step_rmse = math.sqrt(step_error)  # This is the key change!
+
+                print(f"XOR PATTERN: Input={self.data[self.index][0]} → Network={output} → Expected={correct}")
+
+                self.index += 1
+
+                if self.index >= len(self.data):
+                    # Episode finished - calculate final fitness
+                    total_rmse = math.sqrt(self.error_acc + step_rmse)  # Not step_error!
+                    fitness = 1.0 / (total_rmse + 1e-5)
+                    await from_pid.send(("result", fitness, 1))
+                    self.index = 0
+                    self.error_acc = 0.0
+                else:
+                    # Continue episode
+                    self.error_acc += step_rmse  # Add RMSE, not raw error
+                    await from_pid.send(("result", 0.0, 0))
+
+            elif tag == "terminate":
+                return