Example usage for org.apache.mahout.common IntPairWritable getSecond

Introduction

In this page you can find the example usage for org.apache.mahout.common IntPairWritable getSecond.

Prototype

public int getSecond() 

Source Link

Usage

From source file:com.mozilla.grouperfish.mahout.clustering.display.lda.DisplayLDATopics.java

License:Apache License

public static Map<Integer, PriorityQueue<Pair<Double, String>>> getTopWordsByTopics(String stateDirPath,
        Map<Integer, String> featureIndex, int numWordsToPrint) {
    Map<Integer, Double> expSums = new HashMap<Integer, Double>();
    Map<Integer, PriorityQueue<Pair<Double, String>>> queues = new HashMap<Integer, PriorityQueue<Pair<Double, String>>>();
    SequenceFileDirectoryReader reader = null;
    try {/*from w  w w  .  ja  v  a2s.co m*/
        IntPairWritable k = new IntPairWritable();
        DoubleWritable v = new DoubleWritable();
        reader = new SequenceFileDirectoryReader(new Path(stateDirPath));
        while (reader.next(k, v)) {
            int topic = k.getFirst();
            int featureId = k.getSecond();
            if (featureId >= 0 && topic >= 0) {
                double score = v.get();
                Double curSum = expSums.get(topic);
                if (curSum == null) {
                    curSum = 0.0;
                }
                expSums.put(topic, curSum + Math.exp(score));
                String feature = featureIndex.get(featureId);

                PriorityQueue<Pair<Double, String>> q = queues.get(topic);
                if (q == null) {
                    q = new PriorityQueue<Pair<Double, String>>(numWordsToPrint);
                }
                enqueue(q, feature, score, numWordsToPrint);
                queues.put(topic, q);
            }
        }
    } catch (IOException e) {
        LOG.error("Error reading LDA state dir", e);
    } finally {
        if (reader != null) {
            reader.close();
        }
    }

    for (Map.Entry<Integer, PriorityQueue<Pair<Double, String>>> entry : queues.entrySet()) {
        int topic = entry.getKey();
        for (Pair<Double, String> p : entry.getValue()) {
            double score = p.getFirst();
            p.setFirst(Math.exp(score) / expSums.get(topic));
        }
    }

    return queues;
}

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