source: gs3-extensions/mars-src/trunk/src/java/org/greenstone/gsdl3/util/WekaFindInstanceKNN.java@ 36853

/*
 *    WekaFindInstanceKNN.java
 *    Copyright (C) 2011 New Zealand Digital Library, http://www.nzdl.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.
 *
 *    This program is distributed in the hope that it will be useful,
 *    but WITHOUT ANY WARRANTY; without even the implied warranty of
 *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *    GNU General Public License for more details.
 *
 *    You should have received a copy of the GNU General Public License
 *    along with this program; if not, write to the Free Software
 *    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */
package org.greenstone.gsdl3.util;


import weka.core.DenseInstance;
import weka.core.Instance;
import weka.core.Instances;
import weka.core.converters.ConverterUtils.DataSource;

import weka.core.neighboursearch.LinearNNSearch;
import weka.core.neighboursearch.NearestNeighbourSearch;
//import weka.core.neighboursearch.KDTree;

// Based on StackOverflow:
//   https://stackoverflow.com/questions/31350506/how-to-calculate-the-nearest-neighbors-using-weka-from-the-command-line

// The following was also useful as a reference:
//    https://waikato.github.io/weka-blog/posts/2018-10-08-making-a-weka-classifier/

public class WekaFindInstanceKNN 
{

    public static Instances loadDataset(String input_filename) 
    {
    Instances instances = null;

    try {
        DataSource source = new DataSource(input_filename);
        instances = source.getDataSet();
    }
    catch (Exception e) {
        e.printStackTrace();
    }
    
    return instances;
    }

    public static NearestNeighbourSearch initKNN(Instances instances) 
    {
    LinearNNSearch knn = new LinearNNSearch(instances);
    
    return knn;
    }

    public static void printNearestKNN(Instance sample_instance, Instances nearest_instances, 
                      int k_nearest)
    {
    try {
        //cycle through the instances and printout the nearestneighbors

        System.err.println("\n" + sample_instance);
        for(int i =0; i<k_nearest; i++) {
        System.err.println("\t" + nearest_instances.instance(i));
        }   
    }
    catch (Exception e) {
        e.printStackTrace();
    }
        
    }

    static Instances input_instances_ = null;
    static NearestNeighbourSearch knn_ = null;
    
    public static void init(String input_filename)
    {
    if (input_instances_ == null) {
        input_instances_ = loadDataset(input_filename);
    }
    if (knn_ == null) {
        knn_ = initKNN(input_instances_);
    }

    }

    public static Instances kNearestNeighbours(String doc_id_segment, double arousal_val,double valence_val, int k_nearest_num)
    {
    
    Instance sample_instance = new DenseInstance(3);
    sample_instance.setDataset(input_instances_);

    // sample sample:
    //   ds_22716_5743-6,-0.549489,-0.118439
    //sample_instance.setValue(0, "ds_22716_5743-6");
    //sample_instance.setValue(1, -0.549489);
    //sample_instance.setValue(2, -0.118439);

    //String segment_str = Integer.toString(segment);
    //sample_instance.setValue(0, doc_id +"-" + segment_str);

    sample_instance.setValue(0, doc_id_segment);

    sample_instance.setValue(1, arousal_val);
    sample_instance.setValue(2, valence_val);

    Instances nearest_instances = null;
    try {
        nearest_instances = knn_.kNearestNeighbours(sample_instance, k_nearest_num);
        System.err.println("**** nearest_instances len = " + nearest_instances.numInstances());

        //printNearestKNN(sample_instance,nearest_instances, k_nearest_num);

    }
    catch (Exception e) {
        e.printStackTrace();
    }

    return nearest_instances;
    
    }
    
    public static void main(String[] args)
    {
    // First example output, when working through the instances specified in the CSV file
    // (looking for similaries amongst all the instances in the CSV file)

    // ds_22716_5743-6,-0.549489,-0.118439
    //    ds_22761_1171-12,-0.549489,-0.118439
    //    ds_21046_7743-30,-0.549489,-0.118439
    //    ds_24768_23507-6,-0.549489,-0.118439
    //    ds_22761_1171-15,-0.549489,-0.118439

    if (args.length != 2) {
        System.err.println("Usage: k-nearest-num file.{arff,csv}");
        System.exit(1);
    }

    String k_nearest_str     = args[0];
    String input_filename = args[1];
    
    int k_nearest = Integer.parseInt(k_nearest_str);
     
    System.out.println("Weka Command Line Find Nearest " + k_nearest_str
               + " Neighbors for each Instance in "  + input_filename);

    init(input_filename);
    
    //Instances instances = loadDataset(input_filename);
    //NearestNeighbourSearch knn = initKNN(instances);


    Instance sample_instance = new DenseInstance(3);
    sample_instance.setDataset(input_instances_);

    // sample sample:
    //   ds_22716_5743-6,-0.549489,-0.118439
    sample_instance.setValue(0, "ds_22716_5743-6");
    sample_instance.setValue(1, -0.549489);
    sample_instance.setValue(2, -0.118439);

    try {
        Instances nearest_instances = knn_.kNearestNeighbours(sample_instance, k_nearest);
        System.out.println("**** nearest_instances len = " + nearest_instances.numInstances());

        printNearestKNN(sample_instance,nearest_instances, k_nearest);

    }
    catch (Exception e) {
        e.printStackTrace();
    }


 
    }
}