Create ARFF File

AttTest

import java.io.File;

import weka.core.Attribute;
import weka.core.FastVector;
import weka.core.Instance;
import weka.core.Instances;
import weka.core.converters.ArffSaver;
import weka.filters.Filter;
import weka.filters.unsupervised.instance.NonSparseToSparse;


public class AttTest {
    public static void main(String[] args) throws Exception {


        FastVector atts;
        Instances data;
        double[] vals;

        FastVector attZone = new FastVector();
        attZone.addElement("safe_1");
        attZone.addElement("safe_2");
        attZone.addElement("danger_1");

        atts = new FastVector();
        atts.addElement(new Attribute("ref1"));





        atts.addElement(new Attribute("ref2"));
        atts.addElement(new Attribute("ref3"));
        atts.addElement(new Attribute("ref4"));
        atts.addElement(new Attribute("tag"));
        atts.addElement(new Attribute("zone", attZone));


        // 2. create Instances object
        data = new Instances("MyRelation", atts, 0);

        // 3. fill with data
        // first instance
        vals = new double[data.numAttributes()];
        vals[0] = Math.PI;
        vals[1] = 2;
        vals[2] = 33;
        vals[3] = 555;
        vals[4] = 11;
        vals[5] =attZone.indexOf("safe_2");
        data.add(new Instance(1.0, vals));

        NonSparseToSparse nonSparseToSparseInstance = new NonSparseToSparse();
        nonSparseToSparseInstance.setInputFormat(data);
        Instances sparseDataset = Filter.useFilter(data, nonSparseToSparseInstance);
        System.out.println(sparseDataset);
        ArffSaver arffSaverInstance = new ArffSaver();
        arffSaverInstance.setInstances(sparseDataset);
        arffSaverInstance.setFile(new File("/sdcard/ESDN.arff"));
        arffSaverInstance.writeBatch();
    }
}