/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.mahout.classifier.sgd.bankmarketing;

import com.google.common.collect.Lists;
import org.apache.mahout.classifier.evaluation.Auc;
import org.apache.mahout.classifier.sgd.L1;
import org.apache.mahout.classifier.sgd.OnlineLogisticRegression;

import java.util.Collections;
import java.util.List;

/**
 * Uses the SGD classifier on the 'Bank marketing' dataset from UCI.
 *
 * See http://archive.ics.uci.edu/ml/datasets/Bank+Marketing
 *
 * Learn when people accept or reject an offer from the bank via telephone based on income, age, education and more.
 */
public class BankMarketingClassificationMain {

  public static final int NUM_CATEGORIES = 2;

  public static void main(String[] args) throws Exception {
    List<TelephoneCall> calls = Lists.newArrayList(new TelephoneCallParser("bank-full.csv"));

    double heldOutPercentage = 0.10;

    for (int run = 0; run < 20; run++) {
      Collections.shuffle(calls);
      int cutoff = (int) (heldOutPercentage * calls.size());
      List<TelephoneCall> test = calls.subList(0, cutoff);
      List<TelephoneCall> train = calls.subList(cutoff, calls.size());

      OnlineLogisticRegression lr = new OnlineLogisticRegression(NUM_CATEGORIES, TelephoneCall.FEATURES, new L1())
        .learningRate(1)
        .alpha(1)
        .lambda(0.000001)
        .stepOffset(10000)
        .decayExponent(0.2);
      for (int pass = 0; pass < 20; pass++) {
        for (TelephoneCall observation : train) {
          lr.train(observation.getTarget(), observation.asVector());
        }
        if (pass % 5 == 0) {
          Auc eval = new Auc(0.5);
          for (TelephoneCall testCall : test) {
            eval.add(testCall.getTarget(), lr.classifyScalar(testCall.asVector()));
          }
          System.out.printf("%d, %.4f, %.4f\n", pass, lr.currentLearningRate(), eval.auc());
        }
      }
    }
  }
}