ai.preferred.regression.io.ARFFDataReader Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of csvpl Show documentation
Your preferred data manipulation and analysis language for CSV.
The newest version!
/*
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see .
 */

package ai.preferred.regression.io;

import weka.core.*;

import java.io.File;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Set;
import java.util.TreeSet;

public class ARFFDataReader {

  private static double parseDouble(ArrayList record, int row, int col) throws IOException {
    try {
      return Double.parseDouble(record.get(col));
    } catch (NumberFormatException | NullPointerException e) {
      throw new IOException("A number expected! (row = " + row + "; col = " + col + ")");
    }
  }

  private final boolean nominal;
  private final boolean parseHeader;
  private final ArrayList signature;

  public ARFFDataReader(File signatureFile, boolean nominal, boolean parseHeader) throws IOException {
    this.nominal = nominal;
    this.parseHeader = parseHeader;
    try (final CSVInputData data = new CSVInputData(signatureFile, parseHeader)) {
      final ArrayList signature = new ArrayList<>();
      if (nominal) {
        final Set attributeValueSet = new TreeSet<>();
        ArrayList firstRecord = null;
        int row = parseHeader ? 1 : 0;
        for (final ArrayList record : data) {
          if (firstRecord == null) {
            firstRecord = record;
          }
          attributeValueSet.add(record.get(0));
          for (int col = 1; col < record.size(); col++) {
            parseDouble(record, row, col);
          }
          row++;
        }
        if (firstRecord == null) {
          throw new IOException("There is no records in the CSV file!");
        }
        if (data.hasHeader()) {
          final ArrayList header = data.getHeader();
          signature.add(new Attribute(header.get(0), new ArrayList<>(attributeValueSet)));
          for (int i = 1; i < header.size(); i++) {
            signature.add(new Attribute(header.get(i)));
          }
        } else {
          signature.add(new Attribute("Y", new ArrayList<>(attributeValueSet)));
          for (int i = 1; i < firstRecord.size(); i++) {
            signature.add(new Attribute("X" + i));
          }
        }
      } else {
        int row = parseHeader ? 1 : 0;
        if (data.hasHeader()) {
          final ArrayList header = data.getHeader();
          signature.add(new Attribute(header.get(0)));
          for (int i = 1; i < header.size(); i++) {
            signature.add(new Attribute(header.get(i)));
          }
        }
        for (final ArrayList record : data) {
          if (signature.isEmpty()) {
            signature.add(new Attribute("Y"));
            for (int i = 1; i < record.size(); i++) {
              signature.add(new Attribute("X" + i));
            }
          }
          for (int col = 0; col < record.size(); col++) {
            parseDouble(record, row, col);
          }
        }
        if (signature.isEmpty()) {
          throw new IOException("There is no records in the CSV file!");
        }
      }
      this.signature = signature;
    }
  }

  public ArrayList getSignature() {
    return new ArrayList<>(signature);
  }

  public Instances read(File file) throws IOException {
    final Instances instances = new Instances("DATA", signature, 100);
    instances.setClassIndex(0);
    try (final CSVInputData data = new CSVInputData(file, parseHeader)) {
      int row = parseHeader ? 1 : 0;
      for (final ArrayList record : data) {
        final Instance instance = new DenseInstance(instances.numAttributes());
        for (int i = 1; i < record.size(); i++) {
          instance.setValue(i, parseDouble(record, row, i));
        }
        if (nominal) {
          instance.setValue(0, signature.get(0).indexOfValue(record.get(0)));
        } else {
          instance.setValue(0, parseDouble(record, row, 0));
        }
        instances.add(new SparseInstance(instance));
        row++;
      }
    }
    return instances;
  }

}