Added ReLu activation function

.idea/workspace.xml

@@ -4,14 +4,8 @@
     <option name="autoReloadType" value="SELECTIVE" />
   </component>
   <component name="ChangeListManager">
-    <list default="true" id="75a8c215-b746-4a4d-aa16-f3223c12b1ed" name="Changes" comment="Commented out not yet working code">
-      <change afterPath="$PROJECT_DIR$/src/main/java/ActivationFunctions.java" afterDir="false" />
-      <change afterPath="$PROJECT_DIR$/src/main/java/LossFunctions.java" afterDir="false" />
-      <change beforePath="$PROJECT_DIR$/.idea/gradle.xml" beforeDir="false" afterPath="$PROJECT_DIR$/.idea/gradle.xml" afterDir="false" />
-      <change beforePath="$PROJECT_DIR$/.idea/workspace.xml" beforeDir="false" afterPath="$PROJECT_DIR$/.idea/workspace.xml" afterDir="false" />
-      <change beforePath="$PROJECT_DIR$/src/main/java/ActivationLayer.java" beforeDir="false" afterPath="$PROJECT_DIR$/src/main/java/ActivationLayer.java" afterDir="false" />
-      <change beforePath="$PROJECT_DIR$/src/main/java/ExampleXOR.java" beforeDir="false" afterPath="$PROJECT_DIR$/src/main/java/ExampleXOR.java" afterDir="false" />
-      <change beforePath="$PROJECT_DIR$/src/main/java/Network.java" beforeDir="false" afterPath="$PROJECT_DIR$/src/main/java/Network.java" afterDir="false" />
+    <list default="true" id="75a8c215-b746-4a4d-aa16-f3223c12b1ed" name="Changes" comment="Added MAE loss function">
+      <change beforePath="$PROJECT_DIR$/src/main/java/ActivationFunctions.java" beforeDir="false" afterPath="$PROJECT_DIR$/src/main/java/ActivationFunctions.java" afterDir="false" />
     </list>
     <option name="SHOW_DIALOG" value="false" />
     <option name="HIGHLIGHT_CONFLICTS" value="true" />
@@ -103,7 +97,14 @@
       <option name="project" value="LOCAL" />
       <updated>1653168727186</updated>
     </task>
-    <option name="localTasksCounter" value="2" />
+    <task id="LOCAL-00002" summary="Added MAE loss function">
+      <created>1653176561735</created>
+      <option name="number" value="00002" />
+      <option name="presentableId" value="LOCAL-00002" />
+      <option name="project" value="LOCAL" />
+      <updated>1653176561735</updated>
+    </task>
+    <option name="localTasksCounter" value="3" />
     <servers />
   </component>
   <component name="Vcs.Log.Tabs.Properties">
@@ -120,7 +121,8 @@
   <component name="VcsManagerConfiguration">
     <MESSAGE value="Initial commit" />
     <MESSAGE value="Commented out not yet working code" />
-    <option name="LAST_COMMIT_MESSAGE" value="Commented out not yet working code" />
+    <MESSAGE value="Added MAE loss function" />
+    <option name="LAST_COMMIT_MESSAGE" value="Added MAE loss function" />
   </component>
   <component name="com.intellij.coverage.CoverageDataManagerImpl">
     <SUITE FILE_PATH="coverage/JavaNN$ExampleXOR.ic" NAME="ExampleXOR Coverage Results" MODIFIED="1653174521293" SOURCE_PROVIDER="com.intellij.coverage.DefaultCoverageFileProvider" RUNNER="idea" COVERAGE_BY_TEST_ENABLED="false" COVERAGE_TRACING_ENABLED="false" />

src/main/java/ActivationFunctions.java

@@ -36,4 +36,20 @@ public class ActivationFunctions {
     private static double sigma(double value) {
         return 1 / (1 + Math.exp(-value));
     }
+
+    public static SimpleMatrix ReLu(SimpleMatrix A) {
+        SimpleMatrix B = new SimpleMatrix(A);
+        for (int i = 0; i < A.getNumElements(); i++) {
+            B.set(i, Math.max(0, A.get(i)));
+        }
+        return B;
+    }
+
+    public static SimpleMatrix ReLuPrime(SimpleMatrix A) {
+        SimpleMatrix B = new SimpleMatrix(A);
+        for (int i = 0; i < A.getNumElements(); i++) {
+            B.set(i, A.get(i) < 0 ? 0 : 1);
+        }
+        return B;
+    }
 }

src/main/java/FCLayer.java

@@ -9,9 +9,9 @@ public class FCLayer extends Layer {
     public FCLayer(int inputSize, int outputSize) {
         Random random = new Random();
         weights = new SimpleMatrix(inputSize, outputSize, true,
-                random.doubles((long) inputSize*outputSize, -0.5, 0.5).toArray());
+                random.doubles((long) inputSize*outputSize, -1, 1).toArray());
         biases = new SimpleMatrix(1, outputSize, true,
-                random.doubles(outputSize, -0.5, 0.5).toArray());
+                random.doubles(outputSize, -1, 1).toArray());
     }
 
     @Override

src/main/java/LossFunctions.java

@@ -14,4 +14,24 @@ public class LossFunctions {
     public static SimpleMatrix MSEPrime(SimpleMatrix y_true, SimpleMatrix y_pred) {
         return y_true.minus(y_pred).divide((double) y_true.getNumElements()/2);
     }
+
+    public static double MAE(SimpleMatrix y_true, SimpleMatrix y_pred) {
+        double sum = 0;
+        for (int i = 0; i < y_true.getNumElements(); i++) {
+            sum += Math.abs(y_true.get(i) - y_pred.get(i));
+        }
+        return sum / y_true.getNumElements();
+    }
+
+    public static SimpleMatrix MAEPrime(SimpleMatrix y_true, SimpleMatrix y_pred) {
+        SimpleMatrix result = new SimpleMatrix(y_true);
+        for (int i = 0; i < result.getNumElements(); i++) {
+            if (y_true.get(i) < y_pred.get(i)) {
+                result.set(i, 1d);
+            } else {
+                result.set(i, -1d);
+            }
+        }
+        return result;
+    }
 }