org.apache.mahout.classifier.df.data.conditions.Condition Maven / Gradle / Ivy

/**
 * 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.df.data.conditions;

import org.apache.mahout.classifier.df.data.Instance;

/**
 * Condition on Instance
 */
public abstract class Condition {
  
  /**
   * Returns true is the checked instance matches the condition
   * 
   * @param instance
   *          checked instance
   * @return true is the checked instance matches the condition
   */
  public abstract boolean isTrueFor(Instance instance);
  
  /**
   * Condition that checks if the given attribute has a value "equal" to the given value
   */
  public static Condition equals(int attr, double value) {
    return new Equals(attr, value);
  }
  
  /**
   * Condition that checks if the given attribute has a value "lesser" than the given value
   */
  public static Condition lesser(int attr, double value) {
    return new Lesser(attr, value);
  }
  
  /**
   * Condition that checks if the given attribute has a value "greater or equal" than the given value
   */
  public static Condition greaterOrEquals(int attr, double value) {
    return new GreaterOrEquals(attr, value);
  }
}