Example #1
0
  /**
   * Returns the Capabilities of this filter, customized based on the data. I.e., if removes all
   * class capabilities, in case there's not class attribute present or removes the NO_CLASS
   * capability, in case that there's a class present.
   *
   * @param data the data to use for customization
   * @return the capabilities of this object, based on the data
   * @see #getCapabilities()
   */
  public Capabilities getCapabilities(Instances data) {
    Capabilities result;
    Capabilities classes;
    Iterator iter;
    Capability cap;

    result = getCapabilities();

    // no class? -> remove all class capabilites apart from NO_CLASS
    if (data.classIndex() == -1) {
      classes = result.getClassCapabilities();
      iter = classes.capabilities();
      while (iter.hasNext()) {
        cap = (Capability) iter.next();
        if (cap != Capability.NO_CLASS) {
          result.disable(cap);
          result.disableDependency(cap);
        }
      }
    }
    // class? -> remove NO_CLASS
    else {
      result.disable(Capability.NO_CLASS);
      result.disableDependency(Capability.NO_CLASS);
    }

    return result;
  }
Example #2
0
  /**
   * returns a Capabilities object specific for this data. The minimum number of instances is not
   * set, the check for multi-instance data is optional.
   *
   * @param data the data to base the capabilities on
   * @param multi if true then the structure is checked, too
   * @return a data-specific capabilities object
   * @throws Exception in case an error occurrs, e.g., an unknown attribute type
   */
  public static Capabilities forInstances(Instances data, boolean multi) throws Exception {
    Capabilities result;
    Capabilities multiInstance;
    int i;
    int n;
    int m;
    Instance inst;
    boolean missing;

    result = new Capabilities(null);

    // class
    if (data.classIndex() == -1) {
      result.enable(Capability.NO_CLASS);
    } else {
      switch (data.classAttribute().type()) {
        case Attribute.NOMINAL:
          if (data.classAttribute().numValues() == 1) result.enable(Capability.UNARY_CLASS);
          else if (data.classAttribute().numValues() == 2) result.enable(Capability.BINARY_CLASS);
          else result.enable(Capability.NOMINAL_CLASS);
          break;

        case Attribute.NUMERIC:
          result.enable(Capability.NUMERIC_CLASS);
          break;

        case Attribute.STRING:
          result.enable(Capability.STRING_CLASS);
          break;

        case Attribute.DATE:
          result.enable(Capability.DATE_CLASS);
          break;

        case Attribute.RELATIONAL:
          result.enable(Capability.RELATIONAL_CLASS);
          break;

        default:
          throw new UnsupportedAttributeTypeException(
              "Unknown class attribute type '" + data.classAttribute() + "'!");
      }

      // missing class values
      for (i = 0; i < data.numInstances(); i++) {
        if (data.instance(i).classIsMissing()) {
          result.enable(Capability.MISSING_CLASS_VALUES);
          break;
        }
      }
    }

    // attributes
    for (i = 0; i < data.numAttributes(); i++) {
      // skip class
      if (i == data.classIndex()) continue;

      switch (data.attribute(i).type()) {
        case Attribute.NOMINAL:
          result.enable(Capability.UNARY_ATTRIBUTES);
          if (data.attribute(i).numValues() == 2) result.enable(Capability.BINARY_ATTRIBUTES);
          else if (data.attribute(i).numValues() > 2) result.enable(Capability.NOMINAL_ATTRIBUTES);
          break;

        case Attribute.NUMERIC:
          result.enable(Capability.NUMERIC_ATTRIBUTES);
          break;

        case Attribute.DATE:
          result.enable(Capability.DATE_ATTRIBUTES);
          break;

        case Attribute.STRING:
          result.enable(Capability.STRING_ATTRIBUTES);
          break;

        case Attribute.RELATIONAL:
          result.enable(Capability.RELATIONAL_ATTRIBUTES);
          break;

        default:
          throw new UnsupportedAttributeTypeException(
              "Unknown attribute type '" + data.attribute(i).type() + "'!");
      }
    }

    // missing values
    missing = false;
    for (i = 0; i < data.numInstances(); i++) {
      inst = data.instance(i);

      if (inst instanceof SparseInstance) {
        for (m = 0; m < inst.numValues(); m++) {
          n = inst.index(m);

          // skip class
          if (n == inst.classIndex()) continue;

          if (inst.isMissing(n)) {
            missing = true;
            break;
          }
        }
      } else {
        for (n = 0; n < data.numAttributes(); n++) {
          // skip class
          if (n == inst.classIndex()) continue;

          if (inst.isMissing(n)) {
            missing = true;
            break;
          }
        }
      }

      if (missing) {
        result.enable(Capability.MISSING_VALUES);
        break;
      }
    }

    // multi-instance data?
    if (multi) {
      if ((data.numAttributes() == 3)
          && (data.attribute(0).isNominal()) // bag-id
          && (data.attribute(1).isRelationValued()) // bag
          && (data.classIndex() == data.numAttributes() - 1)) {
        multiInstance = new Capabilities(null);
        multiInstance.or(result.getClassCapabilities());
        multiInstance.enable(Capability.NOMINAL_ATTRIBUTES);
        multiInstance.enable(Capability.RELATIONAL_ATTRIBUTES);
        multiInstance.enable(Capability.ONLY_MULTIINSTANCE);
        result.assign(multiInstance);
      }
    }

    return result;
  }