org.apache.hadoop.hive.ql.udf.UDFAcos Maven / Gradle / Ivy
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* Licensed to the Apache Software Foundation (ASF) under one
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* 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,
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* See the License for the specific language governing permissions and
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*/
package org.apache.hadoop.hive.ql.udf;
import org.apache.hadoop.hive.ql.exec.Description;
import org.apache.hadoop.hive.ql.exec.vector.VectorizedExpressions;
import org.apache.hadoop.hive.ql.exec.vector.expressions.gen.FuncACosDoubleToDouble;
import org.apache.hadoop.hive.ql.exec.vector.expressions.gen.FuncACosLongToDouble;
import org.apache.hadoop.hive.serde2.io.DoubleWritable;
/**
* UDFAcos.
*/
@Description(name = "acos",
value = "_FUNC_(x) - returns the arc cosine of x if -1<=x<=1 or " + "NULL otherwise",
extended = "Example:\n"
+ " > SELECT _FUNC_(1) FROM src LIMIT 1;\n"
+ " 0\n"
+ " > SELECT _FUNC_(2) FROM src LIMIT 1;\n"
+ " NULL")
@VectorizedExpressions({FuncACosLongToDouble.class, FuncACosDoubleToDouble.class})
public class UDFAcos extends UDFMath {
private final DoubleWritable result = new DoubleWritable();
/**
* Take Arc Cosine of a in radians.
*/
@Override
protected DoubleWritable doEvaluate(DoubleWritable a) {
double d = a.get();
if (d < -1 || d > 1) {
return null;
} else {
result.set(StrictMath.acos(d));
return result;
}
}
}