@Override
  public void doWork() throws OperatorException {

    ExampleSet exampleSet = exampleSetInput.getData();

    IEntityMapping user_mapping = new EntityMapping();
    IEntityMapping item_mapping = new EntityMapping();
    IRatings training_data = new Ratings();

    if (exampleSet.getAttributes().getSpecial("user identification") == null) {
      throw new UserError(this, 105);
    }

    if (exampleSet.getAttributes().getSpecial("item identification") == null) {
      throw new UserError(this, 105);
    }

    if (exampleSet.getAttributes().getLabel() == null) {
      throw new UserError(this, 105);
    }

    Attributes Att = exampleSet.getAttributes();
    AttributeRole ur = Att.getRole("user identification");
    Attribute u = ur.getAttribute();
    AttributeRole ir = Att.getRole("item identification");
    Attribute i = ir.getAttribute();
    Attribute ui = Att.getLabel();

    for (Example example : exampleSet) {

      double j = example.getValue(u);
      int uid = user_mapping.ToInternalID((int) j);

      j = example.getValue(i);
      int iid = item_mapping.ToInternalID((int) j);

      double r = example.getValue(ui);
      training_data.Add(uid, iid, r);
    }

    _slopeOne recommendAlg = new _slopeOne();

    recommendAlg.user_mapping = user_mapping;
    recommendAlg.item_mapping = item_mapping;
    recommendAlg.SetMinRating(getParameterAsInt("Min Rating"));
    recommendAlg.SetMaxRating(recommendAlg.GetMinRating() + getParameterAsInt("Range"));

    recommendAlg.SetRatings(training_data);

    recommendAlg.Train();

    exampleSetOutput.deliver(exampleSet);

    exampleSetOutput1.deliver(recommendAlg);
  }
  @Override
  public void doWork() throws OperatorException {

    ExampleSet exampleSet = exampleSetInput.getData();

    IPosOnlyFeedback training_data = new PosOnlyFeedback();
    IEntityMapping user_mapping = new EntityMapping();
    IEntityMapping item_mapping = new EntityMapping();

    if (exampleSet.getAttributes().getSpecial("user identification") == null) {
      throw new UserError(this, 105);
    }

    if (exampleSet.getAttributes().getSpecial("item identification") == null) {
      throw new UserError(this, 105);
    }

    Attributes Att = exampleSet.getAttributes();
    AttributeRole ur = Att.getRole("user identification");
    Attribute u = ur.getAttribute();
    AttributeRole ir = Att.getRole("item identification");
    Attribute i = ir.getAttribute();

    for (Example example : exampleSet) {

      double j = example.getValue(u);
      int uid = (int) j;

      j = example.getValue(i);
      int iid = (int) j;

      training_data.Add(user_mapping.ToInternalID(uid), item_mapping.ToInternalID(iid));
      checkForStop();
    }

    System.out.println(training_data.GetMaxItemID() + " " + training_data.GetMaxUserID());

    Random recommendAlg = new Random();
    recommendAlg.SetFeedback(training_data);
    recommendAlg.user_mapping = user_mapping;
    recommendAlg.item_mapping = item_mapping;
    recommendAlg.Train();

    exampleSetOutput.deliver(exampleSet);
    exampleSetOutput1.deliver(recommendAlg);
  }
  /**
   * Applies the sorted and unmachted attribute list to the provided {@link Attributes}. All
   * unmachted attributes are removed from attributes and all {@link Attribute}s from the sorted
   * list are added in correct order.
   *
   * @param sortedAttributeList attributes that will be removed first and added in correct order
   *     afterwards.
   * @param unmachtedAttributes attributes that should be removed. May be <code>null</code> if no
   *     attributes should be removed.
   */
  private void applySortedAttributes(
      List<Attribute> sortedAttributeList,
      List<Attribute> unmachtedAttributes,
      Attributes attributes) {
    if (unmachtedAttributes != null) {
      for (Attribute unmachted : unmachtedAttributes) {
        attributes.remove(unmachted);
      }
    }

    for (Attribute attribute : sortedAttributeList) {
      AttributeRole role = attributes.getRole(attribute);
      attributes.remove(attribute);

      if (role.isSpecial()) {
        attributes.setSpecialAttribute(attribute, role.getSpecialName());
      } else { // regular
        attributes.addRegular(attribute);
      }
    }
  }