public static Pair<DenseMatrixSet<Double>, List<Integer>> createDataSet() throws IOException, IllegalArgumentException {

// load the data

Table dataSetTable = TableDataSetLoader.loadDataSet(new File("src/main/resources/datasets/iris_data.csv"));

List<Integer> labels = new ArrayList<>();

Column species = dataSetTable.column("species");

for (int i = 0; i < species.size(); i++) {

String label = (String) species.get(i);

if(label.equals("Iris-setosa")){

labels.add(0);

}

else if(label.equals("Iris-versicolor")){

labels.add(1);

}

else if(label.equals("Iris-virginica")){

labels.add(2);

}

else{

throw new IllegalArgumentException("Unknown class");

}

}

Table reducedDataSet = dataSetTable.removeColumns("species").first(dataSetTable.rowCount());

DenseMatrixSet<Double> dataSet = new DenseMatrixSet(RowType.Type.DOUBLE_VECTOR, new RowBuilder());

dataSet.initializeFrom(reducedDataSet);

// partition the data set

List<List<Integer>> partitions = RangePartitioner.partition(0, dataSet.m(), 4);

MatrixRowPartitionPolicy partitionPolicy = new MatrixRowPartitionPolicy(partitions);

dataSet.setPartitionPolicy(partitionPolicy);

return PairBuilder.makePair(dataSet, labels);

}

public static void main(String[] args) throws IOException, IllegalArgumentException{

Pair<DenseMatrixSet<Double>, List<Integer>> data = Example8.createDataSet();

ExecutorService executorService = newFixedThreadPool(4);

System.out.println("Number of rows: "+data.first.m());

System.out.println("Number of labels: "+data.second.size());

ThreadedKNNClassifier<Double, DenseMatrixSet<Double>, EuclideanVectorCalculator<Double>,

ClassificationVoter> classifier = new ThreadedKNNClassifier<>(3, false, executorService);

classifier.setDistanceCalculator(new EuclideanVectorCalculator<Double>());

classifier.setMajorityVoter(new ClassificationVoter());

classifier.train(data.first, data.second);

Vector point = new Vector(5.9,3.0,5.1,1.8);

Integer classIdx = classifier.predict(point);

System.out.println("Point "+ point +" has class index "+ classIdx);

executorService.shutdown();

}