samoa-instances/src/main/java/org/apache/samoa/instances/InstancesHeader.java

/*
 * 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.samoa.instances;

/**
 * Class for storing the header or context of a data stream. It allows to know
 * the number of attributes and classes.
 */
public class InstancesHeader extends Instances {

  private static final long serialVersionUID = 1L;

  public InstancesHeader(Instances i) {
    super(i, 0);
  }

  public InstancesHeader() {
    super();
  }

  public static String getClassNameString(InstancesHeader context) {
    if (context == null) {
      return "[class]";
    }
    return "[class:" + context.classAttribute().name() + "]";
  }

  public static String getClassLabelString(InstancesHeader context,
      int classLabelIndex) {
    if ((context == null) || (classLabelIndex >= context.numClasses())) {
      return "<class " + (classLabelIndex + 1) + ">";
    }
    return "<class " + (classLabelIndex + 1) + ":"
    + context.classAttribute().value(classLabelIndex) + ">";
  }

  // is impervious to class index changes - attIndex is true attribute index
  // regardless of class position
  public static String getAttributeNameString(InstancesHeader context,
      int attIndex) {
    if ((context == null) || (attIndex >= context.numAttributes())) {
      return "[att " + (attIndex + 1) + "]";
    }
    int instAttIndex = attIndex < context.classIndex() ? attIndex
        : attIndex + 1;
    return "[att " + (attIndex + 1) + ":"
    + context.attribute(instAttIndex).name() + "]";
  }

  public static String getInputAttributeNameString(InstancesHeader context,
      int attIndex) {
    if ((context == null) || (attIndex >= context.numInputAttributes())) {
      return "[att " + (attIndex + 1) + "]";
    }
    int instAttIndex = attIndex;
    return "[att " + (attIndex + 1) + ":"
    + context.inputAttribute(instAttIndex).name() + "]";
  }

  // is impervious to class index changes - attIndex is true attribute index
  // regardless of class position
  public static String getNominalValueString(InstancesHeader context,
      int attIndex, int valIndex) {
    if (context != null) {
      int instAttIndex = attIndex < context.classIndex() ? attIndex
          : attIndex + 1;
      if ((instAttIndex < context.numAttributes())
          && (valIndex < context.attribute(instAttIndex).numValues())) {
        return "{val " + (valIndex + 1) + ":"
            + context.attribute(instAttIndex).value(valIndex) + "}";
      }
    }
    return "{val " + (valIndex + 1) + "}";
  }

  // is impervious to class index changes - attIndex is true attribute index
  // regardless of class position
  public static String getNumericValueString(InstancesHeader context,
      int attIndex, double value) {
    if (context != null) {
      int instAttIndex = attIndex < context.classIndex() ? attIndex
          : attIndex + 1;
      if (instAttIndex < context.numAttributes()) {
        if (context.attribute(instAttIndex).isDate()) {
          return context.attribute(instAttIndex).formatDate(value);
        }
      }
    }
    return Double.toString(value);
  }

  public Attribute inputAttribute(int w) {
    return this.instanceInformation.inputAttribute(w);
  }

  public Attribute outputAttribute(int w) {
    return this.instanceInformation.outputAttribute(w);
  }

  public int numInputAttributes() {
    return this.instanceInformation.numInputAttributes();
  }

  public int numOutputAttributes() {
    return this.instanceInformation.numOutputAttributes();
  }

  public InstanceInformation getInstanceInformation() {
    return this.instanceInformation;
  }
}