first commit

.classpath

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+<?xml version="1.0" encoding="UTF-8"?>
+<classpath>
+	<classpathentry kind="src" output="target/classes" path="src/main/java">
+		<attributes>
+			<attribute name="optional" value="true"/>
+			<attribute name="maven.pomderived" value="true"/>
+		</attributes>
+	</classpathentry>
+	<classpathentry excluding="**" kind="src" output="target/classes" path="src/main/resources">
+		<attributes>
+			<attribute name="maven.pomderived" value="true"/>
+		</attributes>
+	</classpathentry>
+	<classpathentry kind="src" output="target/test-classes" path="src/test/java">
+		<attributes>
+			<attribute name="optional" value="true"/>
+			<attribute name="maven.pomderived" value="true"/>
+		</attributes>
+	</classpathentry>
+	<classpathentry excluding="**" kind="src" output="target/test-classes" path="src/test/resources">
+		<attributes>
+			<attribute name="maven.pomderived" value="true"/>
+		</attributes>
+	</classpathentry>
+	<classpathentry kind="con" path="org.eclipse.jdt.launching.JRE_CONTAINER/org.eclipse.jdt.internal.debug.ui.launcher.StandardVMType/J2SE-1.5">
+		<attributes>
+			<attribute name="maven.pomderived" value="true"/>
+		</attributes>
+	</classpathentry>
+	<classpathentry kind="con" path="org.eclipse.m2e.MAVEN2_CLASSPATH_CONTAINER">
+		<attributes>
+			<attribute name="maven.pomderived" value="true"/>
+		</attributes>
+	</classpathentry>
+	<classpathentry kind="output" path="target/classes"/>
+</classpath>

.gitignore

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+target
+target/*

.project

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+<?xml version="1.0" encoding="UTF-8"?>
+<projectDescription>
+	<name>mlp</name>
+	<comment></comment>
+	<projects>
+	</projects>
+	<buildSpec>
+		<buildCommand>
+			<name>org.eclipse.jdt.core.javabuilder</name>
+			<arguments>
+			</arguments>
+		</buildCommand>
+		<buildCommand>
+			<name>org.eclipse.m2e.core.maven2Builder</name>
+			<arguments>
+			</arguments>
+		</buildCommand>
+	</buildSpec>
+	<natures>
+		<nature>org.eclipse.jdt.core.javanature</nature>
+		<nature>org.eclipse.m2e.core.maven2Nature</nature>
+	</natures>
+</projectDescription>

.settings/org.eclipse.jdt.core.prefs

@@ -0,0 +1,5 @@
+eclipse.preferences.version=1
+org.eclipse.jdt.core.compiler.codegen.targetPlatform=1.5
+org.eclipse.jdt.core.compiler.compliance=1.5
+org.eclipse.jdt.core.compiler.problem.forbiddenReference=warning
+org.eclipse.jdt.core.compiler.source=1.5

.settings/org.eclipse.m2e.core.prefs

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+activeProfiles=
+eclipse.preferences.version=1
+resolveWorkspaceProjects=true
+version=1

pom.xml

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+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+	<modelVersion>4.0.0</modelVersion>
+	<groupId>com.oscaro</groupId>
+	<artifactId>multiLayerPerceptron</artifactId>
+	<version>0.0.1-SNAPSHOT</version>
+	<name>Multi Layer Perceptron</name>
+	<dependencies>
+		<dependency>
+			<groupId>com.googlecode.json-simple</groupId>
+			<artifactId>json-simple</artifactId>
+			<version>1.1</version>
+		</dependency>
+		<dependency>
+			<groupId>junit</groupId>
+			<artifactId>junit</artifactId>
+			<version>4.12</version>
+			<scope>test</scope>
+		</dependency>	
+	</dependencies>
+</project>

src/main/java/com/oscaro/neuralnetwork/FunctionAbstract.java

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+package com.oscaro.neuralnetwork;
+
+public abstract class FunctionAbstract {
+
+	// Names are useful for debugging to know exactly where it gives...
+	protected String name;
+
+	public String getName() {
+		return name;
+	}
+
+	public FunctionAbstract(String name) throws IllegalArgumentException {
+		if (name == null || name.trim().length() == 0) {
+			throw new IllegalArgumentException(
+					"Name of function should not be null not empty not spaces only");
+		}
+		this.name = name;
+	}
+
+	// Computation of function
+	public abstract float[] run(float[] x) throws IllegalArgumentException;
+
+	// Computation of its derivative
+	public abstract float[] runGradient(float[] intermediateLinearCombination,
+			float[] error) throws IllegalArgumentException;
+}

src/main/java/com/oscaro/neuralnetwork/FunctionLinear.java

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+package com.oscaro.neuralnetwork;
+
+public class FunctionLinear extends FunctionAbstract {
+
+	public FunctionLinear(String s) throws IllegalArgumentException {
+		super(s);
+	}
+
+	@Override
+	public float[] run(float[] x) throws IllegalArgumentException {
+		if (x == null || x.length == 0) {
+			throw new IllegalArgumentException("Input in layer " + getName()
+					+ " should not be null nor empty");
+		}
+		float[] res = new float[x.length];
+		for (int i = 0; i < res.length; i++) {
+			res[i] = x[i]; // Identity
+		}
+		return res;
+	}
+
+	@Override
+	public float[] runGradient(float[] intermediateLinearCombination,
+			float[] error) {
+
+		float[] res = new float[intermediateLinearCombination.length];
+
+		for (int i = 0; i < res.length; i++) {
+			res[i] = error[i]; // * 1.0f the derivative of the identity
+		}
+		return res;
+	}
+
+}

src/main/java/com/oscaro/neuralnetwork/FunctionRelu.java

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+package com.oscaro.neuralnetwork;
+
+public class FunctionRelu extends FunctionAbstract {
+
+	public FunctionRelu(String s) throws IllegalArgumentException {
+		super(s);
+	}
+
+	@Override
+	public float[] run(float[] x) {
+		float[] res = new float[x.length];
+		for (int i = 0; i < res.length; i++) {
+			if (x[i] <= 0) {
+				res[i] = 0.0f;
+			} else {
+				res[i] = x[i];
+			}
+		}
+		return res;
+	}
+
+	@Override
+	public float[] runGradient(float[] intermediateLinearCombination,
+			float[] error) {
+		float[] res = new float[intermediateLinearCombination.length];
+		float tmp;
+		for (int i = 0; i < intermediateLinearCombination.length; i++) {
+			if (intermediateLinearCombination[i] <= 0) {
+				tmp = 0.0f;
+			} else {
+				tmp = 1.0f;
+			}
+			res[i] = tmp * error[i];
+		}
+		return res;
+	}
+
+}

src/main/java/com/oscaro/neuralnetwork/FunctionSigmoid.java

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+package com.oscaro.neuralnetwork;
+
+public class FunctionSigmoid extends FunctionAbstract {
+
+	public FunctionSigmoid(String string) throws IllegalArgumentException {
+		super(string);
+	}
+
+	@Override
+	public float[] run(float[] x) {
+		float[] res = new float[x.length];
+		for (int i = 0; i < res.length; i++) {
+			res[i] = (float) (1.0f / (1.0f + Math.exp(-x[i])));
+		}
+		return res;
+	}
+
+	@Override
+	public float[] runGradient(float[] intermediateLinearCombination,
+			float[] error) {
+
+		float[] tmp = run(intermediateLinearCombination);
+		float[] res = new float[tmp.length];
+
+		for (int i = 0; i < tmp.length; i++) {
+			res[i] = tmp[i] * (1 - tmp[i]) * error[i];
+		}
+		return res;
+	}
+
+}

src/main/java/com/oscaro/neuralnetwork/FunctionSoftmax.java

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+package com.oscaro.neuralnetwork;
+
+import java.util.Arrays;
+
+public class FunctionSoftmax extends FunctionAbstract {
+
+	public FunctionSoftmax(String string) throws IllegalArgumentException {
+		super(string);
+	}
+
+	@Override
+	public float[] run(float[] x) {
+		float[] res = new float[x.length];
+
+		// ValMax is here for numerical stability of the Math.exp function
+		float valMax = Float.NEGATIVE_INFINITY;
+		for (int i = 0; i < x.length; i++) {
+			if (x[i] > valMax) {
+				valMax = x[i];
+			}
+		}
+
+		float z = 0.0f;
+		// Exponentiation
+		for (int i = 0; i < x.length; i++) {
+			// Dividing both numerator and denominator by Math.exp(-valMax) does
+			// not change the result but avoid numerical instability
+			res[i] = (float) (Math.exp(x[i] - valMax));
+			z += res[i];
+		}
+		// Normalization where w is the denominator
+		for (int i = 0; i < x.length; i++) {
+			res[i] = res[i] / z;
+		}
+		return res;
+	}
+
+	@Override
+	public float[] runGradient(float[] intermediateLinearCombination,
+			float[] error)  {
+
+		float[] tmp = run(intermediateLinearCombination);
+
+		float[] res = new float[tmp.length];
+		Arrays.fill(res, 0.0f);
+
+		float delta_ij;
+		for (int i = 0; i < tmp.length; i++) {
+			for (int j = 0; j < tmp.length; j++) {
+				delta_ij = 0.0f;
+				if (i == j) {
+					delta_ij = 1.0f;
+				}
+				res[i] += (tmp[i]) * (delta_ij - (tmp[j])) * error[j];
+			}
+		}
+		return res;
+	}
+}

src/main/java/com/oscaro/neuralnetwork/IllegalArgumentException.java

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+package com.oscaro.neuralnetwork;
+
+public class IllegalArgumentException extends Exception {
+
+	public IllegalArgumentException(String string) {
+		super("com.oscaro.neuralnetwork Exception: " + string);
+	}
+
+	private static final long serialVersionUID = -8029877992021795500L;
+
+}