SortByFeatureUDF.java

/*
 * 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
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package hivemall.ftvec;

import java.util.Map;
import java.util.TreeMap;

import org.apache.hadoop.hive.ql.exec.Description;
import org.apache.hadoop.hive.ql.exec.UDF;
import org.apache.hadoop.hive.ql.udf.UDFType;
import org.apache.hadoop.io.FloatWritable;
import org.apache.hadoop.io.IntWritable;

@Description(name = "sort_by_feature",
        value = "_FUNC_(map in map<int,float>) - Returns a sorted map")
@UDFType(deterministic = true, stateful = false)
public final class SortByFeatureUDF extends UDF {

    public Map<IntWritable, FloatWritable> evaluate(Map<IntWritable, FloatWritable> arg) {
        Map<IntWritable, FloatWritable> ret = new TreeMap<IntWritable, FloatWritable>();
        ret.putAll(arg);
        return ret;
    }

}