/*
* 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.
*/
/*
* CreateInstances.java
* Copyright (C) 2009 University of Waikato, Hamilton, New Zealand
*
*/
package wekaexamples.core;
import weka.core.Attribute;
import weka.core.FastVector;
import weka.core.Instance;
import weka.core.Instances;
/**
* Generates an weka.core.Instances object with different attribute types.
*
* @author FracPete (fracpete at waikato dot ac dot nz)
* @version $Revision: 6052 $
*/
public class CreateInstances {
/**
* Generates the Instances object and outputs it in ARFF format to stdout.
*
* @param args ignored
* @throws Exception if generation of instances fails
*/
public static void main(String[] args) throws Exception {
FastVector atts;
FastVector attsRel;
FastVector attVals;
FastVector attValsRel;
Instances data;
Instances dataRel;
double[] vals;
double[] valsRel;
int i;
// 1. set up attributes
atts = new FastVector();
// - numeric
atts.addElement(new Attribute("att1"));
// - nominal
attVals = new FastVector();
for (i = 0; i < 5; i++)
attVals.addElement("val" + (i+1));
atts.addElement(new Attribute("att2", attVals));
// - string
atts.addElement(new Attribute("att3", (FastVector) null));
// - date
atts.addElement(new Attribute("att4", "yyyy-MM-dd"));
// - relational
attsRel = new FastVector();
// -- numeric
attsRel.addElement(new Attribute("att5.1"));
// -- nominal
attValsRel = new FastVector();
for (i = 0; i < 5; i++)
attValsRel.addElement("val5." + (i+1));
attsRel.addElement(new Attribute("att5.2", attValsRel));
dataRel = new Instances("att5", attsRel, 0);
atts.addElement(new Attribute("att5", dataRel, 0));
// 2. create Instances object
data = new Instances("MyRelation", atts, 0);
// 3. fill with data
// first instance
vals = new double[data.numAttributes()];
// - numeric
vals[0] = Math.PI;
// - nominal
vals[1] = attVals.indexOf("val3");
// - string
vals[2] = data.attribute(2).addStringValue("This is a string!");
// - date
vals[3] = data.attribute(3).parseDate("2001-11-09");
// - relational
dataRel = new Instances(data.attribute(4).relation(), 0);
// -- first instance
valsRel = new double[2];
valsRel[0] = Math.PI + 1;
valsRel[1] = attValsRel.indexOf("val5.3");
dataRel.add(new Instance(1.0, valsRel));
// -- second instance
valsRel = new double[2];
valsRel[0] = Math.PI + 2;
valsRel[1] = attValsRel.indexOf("val5.2");
dataRel.add(new Instance(1.0, valsRel));
vals[4] = data.attribute(4).addRelation(dataRel);
// add
data.add(new Instance(1.0, vals));
// second instance
vals = new double[data.numAttributes()]; // important: needs NEW array!
// - numeric
vals[0] = Math.E;
// - nominal
vals[1] = attVals.indexOf("val1");
// - string
vals[2] = data.attribute(2).addStringValue("And another one!");
// - date
vals[3] = data.attribute(3).parseDate("2000-12-01");
// - relational
dataRel = new Instances(data.attribute(4).relation(), 0);
// -- first instance
valsRel = new double[2];
valsRel[0] = Math.E + 1;
valsRel[1] = attValsRel.indexOf("val5.4");
dataRel.add(new Instance(1.0, valsRel));
// -- second instance
valsRel = new double[2];
valsRel[0] = Math.E + 2;
valsRel[1] = attValsRel.indexOf("val5.1");
dataRel.add(new Instance(1.0, valsRel));
vals[4] = data.attribute(4).addRelation(dataRel);
// add
data.add(new Instance(1.0, vals));
// 4. output data
System.out.println(data);
}
}