machine learning tools, copied from branch confusion-rule

languagetool-dev/pom.xml

@@ -67,6 +67,11 @@
             <artifactId>languagetool-wikipedia</artifactId>
             <version>${languagetool.version}</version>
         </dependency>
+        <dependency>
+            <groupId>org.encog</groupId>
+            <artifactId>encog-core</artifactId>
+            <version>3.2.0</version>
+        </dependency>
 
         <dependency>
             <groupId>junit</groupId>

languagetool-dev/src/main/java/org/languagetool/dev/errorcorpus/MachineLearning.java

@@ -0,0 +1,100 @@
+/* LanguageTool, a natural language style checker 
+ * Copyright (C) 2014 Daniel Naber (http://www.danielnaber.de)
+ * 
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301
+ * USA
+ */
+package org.languagetool.dev.errorcorpus;
+
+import org.encog.Encog;
+import org.encog.engine.network.activation.ActivationSigmoid;
+import org.encog.ml.BasicML;
+import org.encog.ml.data.MLDataSet;
+import org.encog.ml.data.basic.BasicMLData;
+import org.encog.ml.data.basic.BasicMLDataSet;
+import org.encog.neural.networks.BasicNetwork;
+import org.encog.neural.networks.PersistBasicNetwork;
+import org.encog.neural.networks.layers.BasicLayer;
+import org.encog.neural.networks.training.propagation.resilient.ResilientPropagation;
+import org.encog.persist.EncogPersistor;
+
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.FileOutputStream;
+import java.io.IOException;
+
+/**
+ * @since 2.7
+ */
+class MachineLearning implements AutoCloseable {
+
+  private static final double MAX_ERROR = 0.01;
+  private static final double MAX_ITERATIONS = 10_000;
+
+  private final MLDataSet trainingSet = new BasicMLDataSet();
+  private final int neurons;
+
+  MachineLearning(int neurons) {
+    this.neurons = neurons;
+  }
+
+  void addData(double idealValue, double... input) {
+    BasicMLData idealData = new BasicMLData(new double[] {idealValue});
+    trainingSet.add(new BasicMLData(input), idealData);
+  }
+
+  void train(File outputFile) throws IOException {
+    BasicNetwork network = new BasicNetwork();
+    network.addLayer(new BasicLayer(null, true, neurons));
+    network.addLayer(new BasicLayer(new ActivationSigmoid(), false, 4));
+    network.addLayer(new BasicLayer(new ActivationSigmoid(), false, 1));
+    network.getStructure().finalizeStructure();
+    network.reset(1234); // seed to force deterministic results
+
+    ResilientPropagation train = new ResilientPropagation(network, trainingSet);
+    int epoch = 1;
+    do {
+      train.iteration();
+      if (epoch % 1000 == 0) {
+        System.out.println("Epoch #" + epoch + " Error:" + train.getError());
+      }
+      epoch++;
+      if (epoch >= MAX_ITERATIONS) {
+        System.err.println("Warn: maximum iterations (" + MAX_ITERATIONS + ") reached, stopping training");
+        break;
+      }
+    } while (train.getError() > MAX_ERROR);
+    System.out.println("Epoch #" + epoch + " Error:" + train.getError());
+    train.finishTraining();
+
+    EncogPersistor persistor = new PersistBasicNetwork();
+    try (FileOutputStream outputStream = new FileOutputStream(outputFile)) {
+      persistor.save(outputStream, network);
+    }
+  }
+
+  BasicML load(File inputFile) throws IOException {
+    EncogPersistor persistor = new PersistBasicNetwork();
+    try (FileInputStream inputStream = new FileInputStream(inputFile)) {
+      Object read = persistor.read(inputStream);
+      return (BasicML)read;
+    }
+  }
+
+  @Override
+  public void close() {
+    Encog.getInstance().shutdown();
+  }
+}