Fix branch

Author: andrewdalpino

src/NeuralNet/Network.php

@@ -131,6 +131,26 @@ public function layers() : Traversable
         yield $this->output;
     }
 
+    /**
+     * Return the number of trainable parameters in the network.
+     *
+     * @return int
+     */
+    public function numParams() : int
+    {
+        $numParams = 0;
+
+        foreach ($this->layers() as $layer) {
+            if ($layer instanceof Parametric) {
+                foreach ($layer->parameters() as $parameter) {
+                    $numParams += $parameter->param()->size();
+                }
+            }
+        }
+
+        return $numParams;
+    }
+
     /**
      * Initialize the parameters of the layers and warm the optimizer cache.
      */

src/constants.php

@@ -18,7 +18,7 @@
      *
      * @var float
      */
-    const EPSILON = 1e-16;
+    const EPSILON = 1e-8;
 
     /**
      * The natural logarithm of the epsilon constant.