org.apache.lens.ml.algo.spark.DoubleValueMapper Maven / Gradle / Ivy

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/**
 * 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.lens.ml.algo.spark;

/**
 * Directly return input when it is known to be double.
 */
public class DoubleValueMapper extends FeatureValueMapper {

  /*
   * (non-Javadoc)
   *
   * @see org.apache.lens.ml.spark.FeatureValueMapper#call(java.lang.Object)
   */
  @Override
  public final Double call(Object input) {
    if (input instanceof Double || input == null) {
      return input == null ? Double.valueOf(0d) : (Double) input;
    }

    throw new IllegalArgumentException("Invalid input expecting only doubles, but got " + input);
  }
}