playground.johannes.socialnetworks.snowball2.sim.deprecated.Estimator2.java Source code

Introduction

Here is the source code for playground.johannes.socialnetworks.snowball2.sim.deprecated.Estimator2.java

Source

/* *********************************************************************** *
 * project: org.matsim.*
 * Estimator2.java
 *                                                                         *
 * *********************************************************************** *
 *                                                                         *
 * copyright       : (C) 2010 by the members listed in the COPYING,        *
 *                   LICENSE and WARRANTY file.                            *
 * email           : info at matsim dot org                                *
 *                                                                         *
 * *********************************************************************** *
 *                                                                         *
 *   This program is free software; you can redistribute it and/or modify  *
 *   it under the terms of the GNU General Public License as published by  *
 *   the Free Software Foundation; either version 2 of the License, or     *
 *   (at your option) any later version.                                   *
 *   See also COPYING, LICENSE and WARRANTY file                           *
 *                                                                         *
 * *********************************************************************** */
package playground.johannes.socialnetworks.snowball2.sim.deprecated;

import gnu.trove.TIntArrayList;
import gnu.trove.TIntDoubleHashMap;
import gnu.trove.TIntObjectHashMap;
import gnu.trove.TIntObjectIterator;

import org.apache.commons.math.stat.StatUtils;

import playground.johannes.sna.graph.Vertex;
import playground.johannes.sna.snowball.SampledGraph;
import playground.johannes.sna.snowball.SampledVertex;
import playground.johannes.sna.snowball.analysis.PiEstimator;
import playground.johannes.socialnetworks.snowball2.sim.SampleStats;

/**
 * @author illenberger
 *
 */
public class Estimator2 implements PiEstimator {

    private TIntDoubleHashMap kMap;

    private SampleStats stats;

    private final int N;

    public Estimator2(int N) {
        this.N = N;
    }

    @Override
    public double probability(SampledVertex vertex) {
        int it = stats.getMaxIteration();
        int k = vertex.getNeighbours().size();

        if (it == 0) {
            return stats.getAccumulatedNumSampled(it) / (double) N;
        } else if (it == 1) {
            int n = stats.getAccumulatedNumSampled(it - 1);
            return 1 - Math.pow(1 - n / (double) N, k);
        } else {
            double k_neighbor = kMap.get(k);
            double p_neighbor = 1 - Math.pow(1 - stats.getAccumulatedNumSampled(it - 2) / (double) N, k_neighbor);

            double p_k = 1 - Math.pow(1 - p_neighbor, k);

            double p = 1;
            if (vertex.getIterationSampled() == it)
                p = stats.getNumSampled(it) / (double) stats.getNumDetected(it - 1);

            return p * p_k;
        }
    }

    @Override
    public void update(SampledGraph graph) {
        stats = new SampleStats(graph);

        TIntObjectHashMap<TIntArrayList> tmp = new TIntObjectHashMap<TIntArrayList>();

        for (Vertex vertex : graph.getVertices()) {
            if (((SampledVertex) vertex).isSampled()) {
                int k = vertex.getNeighbours().size();
                TIntArrayList values = tmp.get(k);
                if (values == null) {
                    values = new TIntArrayList();
                    tmp.put(k, values);
                }
                for (Vertex neighbor : vertex.getNeighbours()) {
                    if (((SampledVertex) neighbor).isSampled()) {
                        values.add(neighbor.getNeighbours().size());
                    }
                }
            }
        }

        kMap = new TIntDoubleHashMap();
        TIntObjectIterator<TIntArrayList> it = tmp.iterator();
        for (int i = 0; i < tmp.size(); i++) {
            it.advance();
            TIntArrayList list = it.value();
            double[] dList = new double[list.size()];
            for (int k = 0; k < list.size(); k++)
                dList[k] = list.get(k);
            kMap.put(it.key(), StatUtils.geometricMean(dList));
        }
    }

    /* (non-Javadoc)
     * @see org.matsim.contrib.sna.snowball.analysis.PiEstimator#probability(org.matsim.contrib.sna.snowball.SampledVertex, int)
     */
    @Override
    public double probability(SampledVertex vertex, int iteration) {
        // TODO Auto-generated method stub
        return 0;
    }

}