Backpropagation in synapse

Runtime/Scripts/Core/Synapse.cs

@@ -1,5 +1,6 @@
 using System;
 using UnityEngine;
+using Unity.Mathematics;
 
 namespace NanoBrain {
 
@@ -31,6 +32,20 @@ namespace NanoBrain {
             this.weight = weight;
         }
 
+        public virtual void BasicBackPropagation(float error, float learningRate) {
+            float derivative = error;
+            switch (neuron.activator) {
+                case Neuron.ActivationType.Linear:
+                    derivative *= 1;
+                    break;
+                default:
+                    break;
+            }
+            derivative *= math.length(neuron.activation);
+
+            float deltaWeight = learningRate * derivative;
+            this.weight += deltaWeight;
+        }
     }
 
 }