ValueIterationTest.java

package aima.test.core.unit.probability.mdp;

import java.util.Map;

import org.junit.Assert;
import org.junit.Before;
import org.junit.Test;

import aima.core.environment.cellworld.Cell;
import aima.core.environment.cellworld.CellWorld;
import aima.core.environment.cellworld.CellWorldAction;
import aima.core.environment.cellworld.CellWorldFactory;
import aima.core.probability.example.MDPFactory;
import aima.core.probability.mdp.MarkovDecisionProcess;
import aima.core.probability.mdp.search.ValueIteration;

/**
 * @author Ravi Mohan
 * @author Ciaran O'Reilly
 * 
 */
public class ValueIterationTest {
	public static final double DELTA_THRESHOLD = 1e-3;

	private CellWorld<Double> cw = null;
	private MarkovDecisionProcess<Cell<Double>, CellWorldAction> mdp = null;
	private ValueIteration<Cell<Double>, CellWorldAction> vi = null;

	@Before
	public void setUp() {
		cw = CellWorldFactory.createCellWorldForFig17_1();
		mdp = MDPFactory.createMDPForFigure17_3(cw);
		vi = new ValueIteration<Cell<Double>, CellWorldAction>(1.0);
	}

	@Test
	public void testValueIterationForFig17_3() {
		Map<Cell<Double>, Double> U = vi.valueIteration(mdp, 0.0001);

		Assert.assertEquals(0.705, U.get(cw.getCellAt(1, 1)), DELTA_THRESHOLD);
		Assert.assertEquals(0.762, U.get(cw.getCellAt(1, 2)), DELTA_THRESHOLD);
		Assert.assertEquals(0.812, U.get(cw.getCellAt(1, 3)), DELTA_THRESHOLD);

		Assert.assertEquals(0.655, U.get(cw.getCellAt(2, 1)), DELTA_THRESHOLD);
		Assert.assertEquals(0.868, U.get(cw.getCellAt(2, 3)), DELTA_THRESHOLD);

		Assert.assertEquals(0.611, U.get(cw.getCellAt(3, 1)), DELTA_THRESHOLD);
		Assert.assertEquals(0.660, U.get(cw.getCellAt(3, 2)), DELTA_THRESHOLD);
		Assert.assertEquals(0.918, U.get(cw.getCellAt(3, 3)), DELTA_THRESHOLD);

		Assert.assertEquals(0.388, U.get(cw.getCellAt(4, 1)), DELTA_THRESHOLD);
		Assert.assertEquals(-1.0, U.get(cw.getCellAt(4, 2)), DELTA_THRESHOLD);
		Assert.assertEquals(1.0, U.get(cw.getCellAt(4, 3)), DELTA_THRESHOLD);
	}
}