ANN

Esiur.Analysis/Neural/ActivationFunction.cs

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+using System;
+using System.Collections.Generic;
+using System.Text;
+
+namespace Esiur.Analysis.Neural
+{
+    public delegate double ActivationFunction(double value);
+
+    public static class ActivationFunctions
+    {
+
+        public static (ActivationFunction, ActivationFunction) Sigmoid()
+        {
+            return (new ActivationFunction(x =>
+            {
+                float k = (float)Math.Exp(x);
+                return k / (1.0 + k);
+            }),
+              new ActivationFunction(x =>
+             {
+                 return x * (1 - x);
+             }));
+        }
+
+        public static ActivationFunction Tanh()
+        {
+            return new ActivationFunction(x =>
+            {
+                return Math.Tanh(x);
+            });
+        }
+
+
+        public static ActivationFunction ReLU()
+        {
+            return new ActivationFunction(x =>
+            {
+                return (0 >= x) ? 0 : x;
+            });
+        }
+
+        public static ActivationFunction LeakyReLU()
+        {
+            return new ActivationFunction(x =>
+            {
+                return (0 >= x) ? 0.01 * x : x;
+            });
+        }
+
+        public static ActivationFunction SigmoidDer()
+        {
+            return new ActivationFunction(x =>
+            {
+                return x * (1 - x);
+            });
+        }
+
+        public static ActivationFunction TanhDer()
+        {
+            return new ActivationFunction(x =>
+            {
+                return 1 - (x * x);
+            });
+        }
+
+        public static ActivationFunction ReLUDer()
+        {
+            return new ActivationFunction(x =>
+            {
+                return (0 >= x) ? 0 : 1;
+            });
+        }
+
+        public static ActivationFunction LeakyReLUDer()
+        {
+            return new ActivationFunction(x =>
+            {
+                return (0 >= x) ? 0.01f : 1;
+            });
+        }
+
+
+
+        
+    }
+
+}