/**
* 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.tajo.engine.function.math;
import org.apache.tajo.catalog.Column;
import org.apache.tajo.common.TajoDataTypes;
import org.apache.tajo.datum.Datum;
import org.apache.tajo.datum.DatumFactory;
import org.apache.tajo.datum.NullDatum;
import org.apache.tajo.engine.function.GeneralFunction;
import org.apache.tajo.engine.function.annotation.Description;
import org.apache.tajo.engine.function.annotation.ParamTypes;
import org.apache.tajo.storage.Tuple;
/**
* Function definition
*
* Float8 atan2(value FLOAT8, value FLOAT8)
*/
@Description(
functionName = "atan2",
description = "Inverse tangent of y/x.",
example = "> SELECT atan(y,x);",
returnType = TajoDataTypes.Type.FLOAT8,
paramTypes = {@ParamTypes(paramTypes = {TajoDataTypes.Type.FLOAT4, TajoDataTypes.Type.FLOAT4}),
@ParamTypes(paramTypes = {TajoDataTypes.Type.FLOAT8, TajoDataTypes.Type.FLOAT8})}
)
public class Atan2 extends GeneralFunction {
public Atan2() {
super(new Column[] {
new Column("y", TajoDataTypes.Type.FLOAT8),
new Column("x", TajoDataTypes.Type.FLOAT8)
});
}
@Override
public Datum eval(Tuple params) {
Datum valueDatumx = params.get(0);
Datum valueDatumy = params.get(1);
if(valueDatumx instanceof NullDatum || valueDatumy instanceof NullDatum) {
return NullDatum.get();
}
return DatumFactory.createFloat8(Math.atan2(valueDatumx.asFloat8(), valueDatumy.asFloat8()));
}
}