/**
* 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.hadoop.hive.ql.udf;
import org.apache.hadoop.hive.ql.exec.Description;
import org.apache.hadoop.hive.ql.exec.UDF;
import org.apache.hadoop.hive.serde2.io.DoubleWritable;
/**
* UDFPower.
*
*/
@Description(name = "power,pow",
value = "_FUNC_(x1, x2) - raise x1 to the power of x2",
extended = "Example:\n"
+ " > SELECT _FUNC_(2, 3) FROM src LIMIT 1;\n" + " 8")
public class UDFPower extends UDF {
private DoubleWritable result = new DoubleWritable();
public UDFPower() {
}
/**
* Raise a to the power of b.
*/
public DoubleWritable evaluate(DoubleWritable a, DoubleWritable b) {
if (a == null || b == null) {
return null;
} else {
result.set(Math.pow(a.get(), b.get()));
return result;
}
}
}