/* ChebyshevIIRDesignerTest.java created 2010-09-14
 *
 */

package org.signalml.math.iirdesigner;

import static org.signalml.math.iirdesigner.IIRDesignerAssert.*;

import org.junit.Test;
import java.lang.Math.*;

import org.signalml.math.iirdesigner.BadFilterParametersException;
import org.signalml.math.iirdesigner.Chebyshev1IIRDesigner;
import org.signalml.math.iirdesigner.ChebyshevIIRDesigner;
import org.signalml.math.iirdesigner.FilterType;
import org.signalml.math.iirdesigner.AbstractIIRDesigner.BandstopObjectiveFunction;

/**
 * This class performs unit tests on {@link ChebyshevIIRDesigner} class.
 *
 * @author Piotr Szachewicz
 */
public class ChebyshevIIRDesignerTest {

	/**
	 * an instance of {@link Chebyshev1IIRDesigner} needed to call all the test methods
	 */
	Chebyshev1IIRDesigner iirdesigner = new Chebyshev1IIRDesigner();

	/**
	 * Test method for {@link ChebyshevIIRDesigner#calculateFilterOrder(org.signalml.math.iirdesigner.FilterType, double[], double[], double, double, boolean) }.
	 */
	@Test
	public void testCalculateFilterOrder() throws BadFilterParametersException {

		int filterOrder;

		//digital lowpass
		filterOrder = iirdesigner.calculateFilterOrder(FilterType.LOWPASS, 0.4, 0.7, 3, 40, false);
		assertEquals(4, filterOrder);

		//digital highpass
		filterOrder = iirdesigner.calculateFilterOrder(FilterType.HIGHPASS, 0.7, 0.3, 1, 80, false);
		assertEquals(6, filterOrder);

		//digital bandstop
		filterOrder = iirdesigner.calculateFilterOrder(FilterType.BANDSTOP, new double[] {0.5, 0.8}, new double[] {0.6, 0.7}, 0.5, 100, false);
		assertEquals(8, filterOrder);

		//analog bandpass
		filterOrder = iirdesigner.calculateFilterOrder(FilterType.BANDPASS, new double[] {0.6, 0.7}, new double[] {0.55, 0.8}, 0.5, 100, true);
		assertEquals(10, filterOrder);

	}

	/**
	 * Test method for {@link ChebyshevIIRDesigner#calculateBandstopObjectiveFunctionValue(double, int, double[], double[], double, double) }.
	 */
	@Test
	public void testBandstopObjectiveFunction() {

		//chebyshev test (both chebyshev's are implemented by the same code)
		BandstopObjectiveFunction bo = iirdesigner.new BandstopObjectiveFunction(0,
									   new double[] {0.1, 0.8},
									   new double[] {0.4, 0.6},
									   3, 20);
		assertEquals(3.7599806708583481, bo.value(0.0), 1e-8);

	}

}