Attempts to fix genetic training

src/main.nim

@@ -7,6 +7,7 @@ import std/tables
 import std/math
 import std/random
 import std/algorithm
+import std/strformat
 
 
 ## A bunch of activation functions
@@ -27,28 +28,29 @@ func ind2sub(n: int, shape: tuple[rows, cols: int]): tuple[row, col: int] =
 
 proc loss(params: TableRef[string, float]): float =
     ## Our loss function for tris
-    result = params["moves"]
-    if int(params["result"]) == GameStatus.Draw.int:
-        result += 6.0
-    elif int(params["result"]) == GameStatus.Lose.int:
-        result += 12.0
-    result = sigmoid(result)
+    if params.hasKey("sameMove"):
+        result = 24 - params["moves"]
+    else:
+        result = params["moves"]
+        if int(params["result"]) == GameStatus.Draw.int:
+            result += 6
+        elif int(params["result"]) == GameStatus.Lose.int:
+            result += 12
+    echo result
 
 
 proc compareNetworks(a, b: NeuralNetwork): int =
+    if a.params.len() == 0:
+        return -1
+    elif b.params.len() == 0:
+        return 1
     return cmp(loss(a.params), loss(b.params))
 
 
 proc crossover(a, b: NeuralNetwork): NeuralNetwork =
     result = deepCopy(a)
-    for i, layer in a.layers:
-        result.layers[i].weights = layer.weights.copy()
-        result.layers[i].biases = layer.biases.copy()
     var i = 0
     while i < a.layers.len():
-        result.layers[i] = new(Layer)
-        result.layers[i].inputSize = a.layers[i].inputSize
-        result.layers[i].outputSize = a.layers[i].outputSize
         # We inherit 50% of our weights and biases from our first 
         # parent and the other 50% from the other parent
         result.layers[i].weights = where(rand[float](a.layers[i].weights.shape) >= 0.5, a.layers[i].weights, b.layers[i].weights)
@@ -65,23 +67,25 @@ proc crossover(a, b: NeuralNetwork): NeuralNetwork =
 
 
 ## Our training program
-const Population = 2
-const Iterations = 100
+const Population = 100
+const Iterations = 300
 const Epochs = 10
-const Take = 2
+const Take = 15
 
 
 var networks: seq[NeuralNetwork] = @[]
+var best: seq[NeuralNetwork] = @[]
 for _ in 0..<Population:
-    networks.add(newNeuralNetwork(@[9, 8, 10, 9], activationFunc=newActivation(sigmoid, func (x, y: float): float = 0.0), 
-                          lossFunc=newLoss(loss, func (x, y: float): float = 0.0), weightRange=(-1.0, +1.0), learnRate=0.02))
+    networks.add(newNeuralNetwork(@[9, 16, 12, 9], activationFunc=newActivation(sigmoid, func (x, y: float): float = 0.0), 
+                          lossFunc=newLoss(loss, func (x, y: float): float = 0.0), weightRange=(-1.0, +1.0), biasRange=(-0.5, 0.5), 
+                          learnRate=0.02))
 
 var gameOne: TrisGame
 var gameTwo: TrisGame
 var one: NeuralNetwork
 var two: NeuralNetwork
 var pos: tuple[row, col: int]
-var lost: bool = false
+
 for epoch in 0..<Epochs:
     for iteration in 0..<Iterations:
         gameOne = newTrisGame()
@@ -99,21 +103,21 @@ for epoch in 0..<Epochs:
                 # We consider this a loss
                 one.params["result"] = float(Lose)
                 two.params["result"] = float(Lose)
-                lost = true
+                one.params["sameMove"] = 1.0
+                two.params["sameMove"] = 1.0
                 break
             gameTwo.place(TileKind.Self, pos.row, pos.col)
             gameOne.place(TileKind.Enemy, pos.row, pos.col)
-        if not lost:
+        if not one.params.hasKey("sameMove"):
             one.params["result"] = gameOne.get().float()
             two.params["result"] = gameTwo.get().float()
-        else:
-            lost = false
         one.params["moves"] = gameOne.moves.float()
         two.params["moves"] = gameTwo.moves.float()
     networks.sort(cmp=compareNetworks)
-    networks = networks[0..<Take]
-    one = sample(networks)
-    two = sample(networks)
-    while one == two:
-        two = sample(networks)
-    networks.add(one.crossover(two))
+    best = networks[0..<Take]
+    while networks.len() < Population:
+        one = sample(best)
+        two = sample(best)
+        while one == two:
+            two = sample(best)
+        networks.add(one.crossover(two))

src/nn/network.nim

@@ -85,7 +85,7 @@ proc newActivation*(function: proc (input: float): float {.noSideEffect.}, deriv
     result.derivative = derivative
 
 
-proc newLayer*(inputSize: int, outputSize: int, weightRange: tuple[start, stop: float]): Layer =
+proc newLayer*(inputSize: int, outputSize: int, weightRange, biasRange: tuple[start, stop: float]): Layer =
     ## Creates a new layer with inputSize input 
     ## parameters and outputSize outgoing outputs.
     ## Weights are initialized with random values
@@ -96,7 +96,7 @@ proc newLayer*(inputSize: int, outputSize: int, weightRange: tuple[start, stop:
     var biases = newSeqOfCap[float](outputSize)
     var biasGradients = newSeqOfCap[float](outputSize)
     for _ in 0..<outputSize:
-        biases.add(0.0)
+        biases.add(rand(biasRange.start..biasRange.stop))
         biasGradients.add(0.0)
     var weights = newSeqOfCap[seq[float]](inputSize * outputSize)
     var weightGradients = newSeqOfCap[seq[float]](inputSize * outputSize)
@@ -113,13 +113,13 @@ proc newLayer*(inputSize: int, outputSize: int, weightRange: tuple[start, stop:
     
 
 proc newNeuralNetwork*(layers: seq[int], activationFunc: Activation, lossFunc: Loss,
-                       learnRate: float, weightRange: tuple[start, stop: float]): NeuralNetwork =
+                       learnRate: float, weightRange, biasRange: tuple[start, stop: float]): NeuralNetwork =
     ## Initializes a new neural network
     ## with the given layer layout
     new(result)
     result.layers = newSeqOfCap[Layer](len(layers))
     for i in 0..<layers.high():
-        result.layers.add(newLayer(layers[i], layers[i + 1], weightRange))
+        result.layers.add(newLayer(layers[i], layers[i + 1], weightRange, biasRange))
     result.activation = activationFunc
     result.loss = lossFunc
     result.learnRate = learnRate