.

optim_nn.py

@@ -98,7 +98,7 @@ class Momentum(Optimizer):
             self.dWprev = np.copy(dW)
 
         V = self.mu * self.dWprev - self.alpha * (dW + W * self.lamb)
-        self.dWprev = V
+        self.dWprev[:] = V
         if self.nesterov:
             return self.mu * V - self.alpha * (dW + W * self.lamb)
         else:
@@ -412,7 +412,7 @@ class Model:
                 offset += node.size
 
     def traverse(self, nodes, node):
-        if node == x:
+        if node == self.x:
             return [node]
         for parent in node.parents:
             if parent not in nodes:
@@ -465,6 +465,60 @@ class Model:
     def save_weights(self, fn, overwrite=False):
         raise NotImplementedError("unimplemented", self)
 
+class Ritual:
+    def __init__(self,
+        optim=None,
+        learn_rate=1e-3, learn_anneal=1, learn_advance=0,
+        loss=None, mloss=None):
+        self.optim = optim if optim is not None else SGD()
+        self.loss = loss if loss is not None else Squared()
+        self.mloss = mloss if mloss is not None else loss
+        self.learn_rate = nf(learn_rate)
+        self.learn_anneal = nf(learn_anneal)
+        self.learn_advance = nf(learn_advance)
+
+    def measure(self, residual):
+        return self.mloss.mean(residual)
+
+    def derive(self, residual):
+        return self.loss.dmean(residual)
+
+    def update(self, dW, W):
+        self.optim.update(dW, W)
+
+    def prepare(self, epoch):
+        self.optim.alpha = self.learn_rate * self.learn_anneal**epoch
+
+    def restart(self, optim=False):
+        self.learn_rate *= self.learn_anneal**self.learn_advance
+        if optim:
+            self.optim.reset()
+
+    def train_batched(self, model, inputs, outputs, batch_size, return_losses=False):
+        cumsum_loss = 0
+        batch_count = inputs.shape[0] // batch_size
+        losses = []
+        for b in range(batch_count):
+            bi = b * batch_size
+            batch_inputs  = inputs[ bi:bi+batch_size]
+            batch_outputs = outputs[bi:bi+batch_size]
+
+            predicted = model.forward(batch_inputs)
+            residual = predicted - batch_outputs
+
+            model.backward(self.derive(residual))
+            self.update(model.dW, model.W)
+
+            batch_loss = self.measure(residual)
+            cumsum_loss += batch_loss
+            if return_losses:
+                losses.append(batch_loss)
+        avg_loss = cumsum_loss / batch_count
+        if return_losses:
+            return avg_loss, losses
+        else:
+            return avg_loss
+
 def multiresnet(x, width, depth, block=2, multi=1, activation=Relu, style='batchless'):
     y = x
     last_size = x.output_shape[0]
@@ -516,7 +570,7 @@ def multiresnet(x, width, depth, block=2, multi=1, activation=Relu, style='batch
 
     return y
 
-if __name__ == '__main__':
+def run(program, args=[]):
     import sys
     lament = lambda *args, **kwargs: print(*args, file=sys.stderr, **kwargs)
     def log(left, right):
@@ -527,6 +581,7 @@ if __name__ == '__main__':
     from dotmap import DotMap
     config = DotMap(
         fn = 'ml/cie_mlp_min.h5',
+        log_fn = 'losses.npz',
 
         # multi-residual network parameters
         res_width = 49,
@@ -553,7 +608,6 @@ if __name__ == '__main__':
         batch_size = 64,
         init = 'he_normal',
         loss = SomethingElse(4/3),
-        log_fn = 'losses.npz',
         mloss = 'mse',
         restart_optim = True, # restarts also reset internal state of optimizer
         unsafe = True, # aka gotta go fast mode
@@ -632,11 +686,14 @@ if __name__ == '__main__':
     loss = lookup_loss(config.loss)
     mloss = lookup_loss(config.mloss) if config.mloss else loss
 
-    LR = config.LR
-    LRprod = 0.5**(1/config.LR_halve_every)
+    anneal = 0.5**(1/config.LR_halve_every)
+    ritual = Ritual(optim=optim,
+                    learn_rate=config.LR, learn_anneal=anneal,
+                    learn_advance=config.LR_restart_advance,
+                    loss=loss, mloss=mloss)
 
-    LRE = LR * (LRprod**config.LR_restart_advance)**config.restarts * LRprod**(config.epochs - 1)
-    log("final learning rate", "{:10.8f}".format(LRE))
+    learn_end = config.LR * (anneal**config.LR_restart_advance)**config.restarts * anneal**(config.epochs - 1)
+    log("final learning rate", "{:10.8f}".format(learn_end))
 
     # Training
 
@@ -645,24 +702,21 @@ if __name__ == '__main__':
     valid_losses = []
 
     def measure_error():
-    #   log("weight mean", "{:11.7f}".format(np.mean(model.W)))
-    #   log("weight var",  "{:11.7f}".format(np.var(model.W)))
-
         def print_error(name, inputs, outputs, comparison=None):
             predicted = model.forward(inputs)
             residual = predicted - outputs
-            err = mloss.mean(residual)
+            err = ritual.measure(residual)
             log(name + " loss", "{:11.7f}".format(err))
             if comparison:
                 log("improvement", "{:+7.2f}%".format((comparison / err - 1) * 100))
             return err
 
         train_err = print_error("train",
-                    inputs / x_scale, outputs / y_scale,
-                    config.train_compare)
+                                inputs / x_scale, outputs / y_scale,
+                                config.train_compare)
         valid_err = print_error("valid",
-                    valid_inputs / x_scale, valid_outputs / y_scale,
-                    config.valid_compare)
+                                valid_inputs / x_scale, valid_outputs / y_scale,
+                                config.valid_compare)
         train_losses.append(train_err)
         valid_losses.append(valid_err)
 
@@ -671,38 +725,25 @@ if __name__ == '__main__':
 
         if i > 0:
             log("restarting", i)
-            LR *= LRprod**config.LR_restart_advance
-            if config.restart_optim:
-                optim.reset()
+            ritual.restart(optim=config.restart_optim)
 
         assert inputs.shape[0] % config.batch_size == 0, \
                "inputs is not evenly divisible by batch_size" # TODO: lift this restriction
-        batch_count = inputs.shape[0] // config.batch_size
         for e in range(config.epochs):
             indices = np.arange(inputs.shape[0])
             np.random.shuffle(indices)
             shuffled_inputs = inputs[indices] / x_scale
             shuffled_outputs = outputs[indices] / y_scale
 
-            optim.alpha = LR * LRprod**e
-            #log("learning rate", "{:10.8f}".format(optim.alpha))
+            ritual.prepare(e)
+            #log("learning rate", "{:10.8f}".format(ritual.optim.alpha))
 
-            cumsum_loss = 0
-            for b in range(batch_count):
-                bi = b * config.batch_size
-                batch_inputs  = shuffled_inputs[ bi:bi+config.batch_size]
-                batch_outputs = shuffled_outputs[bi:bi+config.batch_size]
-
-                predicted = model.forward(batch_inputs)
-                residual = predicted - batch_outputs
-                dW = model.backward(loss.dmean(residual))
-                optim.update(dW, model.W)
-
-                # note: we don't actually need this for training, only monitoring.
-                batch_loss = mloss.mean(residual)
-                cumsum_loss += batch_loss
-                batch_losses.append(batch_loss)
-            #log("average loss", "{:11.7f}".format(cumsum_loss / batch_count))
+            avg_loss, losses = ritual.train_batched(model,
+                shuffled_inputs, shuffled_outputs,
+                config.batch_size,
+                return_losses=True)
+            log("average loss", "{:11.7f}".format(avg_loss))
+            batch_losses += losses
 
     measure_error()
 
@@ -723,3 +764,9 @@ if __name__ == '__main__':
                             batch_losses=nfa(batch_losses),
                             train_losses=nfa(train_losses),
                             valid_losses=nfa(valid_losses))
+
+    return 0
+
+if __name__ == '__main__':
+    import sys
+    sys.exit(run(sys.argv[0], sys.argv[1:]))