org.apache.solr.client.solrj.io.eval.FrequencyTableEvaluator.java Source code

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Here is the source code for org.apache.solr.client.solrj.io.eval.FrequencyTableEvaluator.java

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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.solr.client.solrj.io.eval;

import java.io.IOException;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Locale;
import java.util.Map;

import org.apache.commons.math3.stat.Frequency;

import org.apache.solr.client.solrj.io.Tuple;
import org.apache.solr.client.solrj.io.stream.expr.StreamExpression;
import org.apache.solr.client.solrj.io.stream.expr.StreamFactory;

public class FrequencyTableEvaluator extends RecursiveNumericEvaluator implements ManyValueWorker {
    protected static final long serialVersionUID = 1L;

    public FrequencyTableEvaluator(StreamExpression expression, StreamFactory factory) throws IOException {
        super(expression, factory);

        if (containedEvaluators.size() < 1) {
            throw new IOException(
                    String.format(Locale.ROOT, "Invalid expression %s - expecting at least one value but found %d",
                            expression, containedEvaluators.size()));
        }
    }

    @Override
    public Object doWork(Object... values) throws IOException {
        if (Arrays.stream(values).anyMatch(item -> null == item)) {
            return null;
        }

        List<?> sourceValues;

        if (values.length == 1) {
            sourceValues = values[0] instanceof List<?> ? (List<?>) values[0] : Arrays.asList(values[0]);
        } else {
            throw new IOException(
                    String.format(Locale.ROOT, "Invalid expression %s - expecting at least one value but found %d",
                            toExpression(constructingFactory), containedEvaluators.size()));
        }

        Frequency frequency = new Frequency();

        for (Object o : sourceValues) {
            Number number = (Number) o;
            frequency.addValue(number.longValue());
        }

        List<Tuple> histogramBins = new ArrayList<>();

        Iterator iterator = frequency.valuesIterator();

        while (iterator.hasNext()) {
            Long value = (Long) iterator.next();
            Map<String, Number> map = new HashMap<>();
            map.put("value", value.longValue());
            map.put("count", frequency.getCount(value));
            map.put("cumFreq", frequency.getCumFreq(value));
            map.put("cumPct", frequency.getCumPct(value));
            map.put("pct", frequency.getPct(value));
            histogramBins.add(new Tuple(map));
        }
        return histogramBins;
    }
}