/**
 * Copyright (c) 2011, The University of Southampton and the individual contributors.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without modification,
 * are permitted provided that the following conditions are met:
 *
 *   * 	Redistributions of source code must retain the above copyright notice,
 * 	this list of conditions and the following disclaimer.
 *
 *   *	Redistributions in binary form must reproduce the above copyright notice,
 * 	this list of conditions and the following disclaimer in the documentation
 * 	and/or other materials provided with the distribution.
 *
 *   *	Neither the name of the University of Southampton nor the names of its
 * 	contributors may be used to endorse or promote products derived from this
 * 	software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
 * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
package org.openimaj.math.geometry.shape;

import static org.junit.Assert.assertArrayEquals;

import java.util.ArrayList;
import java.util.List;

import org.junit.Test;
import org.openimaj.math.geometry.point.Point2dImpl;
import org.openimaj.math.geometry.point.PointList;

import cern.jet.random.Normal;
import cern.jet.random.Uniform;
import cern.jet.random.engine.MersenneTwister;

/**
 * Tests for {@link PointDistributionModel}s.
 * 
 * @author Jonathon Hare (jsh2@ecs.soton.ac.uk)
 * 
 */
public class PointDistributionModelTest {
	MersenneTwister twister = new MersenneTwister();
	Uniform uniform = new Uniform(twister);

	PointList randomTriangle(Normal rndX, Normal rndY) {
		return new Triangle(
				new Point2dImpl(0 + (float) rndX.nextDouble(), 0 + (float) rndY.nextDouble()),
				new Point2dImpl(1 + (float) rndX.nextDouble(), 1 + (float) rndY.nextDouble()),
				new Point2dImpl(1 + (float) rndX.nextDouble(), 0 + (float) rndY.nextDouble())).asPolygon();
	}

	List<PointList> generateSamples() {
		final List<PointList> list = new ArrayList<PointList>();

		final Normal rndX = new Normal(0, 0.2, twister);
		final Normal rndY = new Normal(0, 0.02, twister);

		for (int i = 0; i < 100; i++) {
			list.add(randomTriangle(rndX, rndY));
		}

		return list;
	}

	/**
	 * Test model fitting
	 */
	@Test
	public void testFitting() {
		final List<PointList> samples = generateSamples();
		final PointDistributionModel pdm = new PointDistributionModel(samples);
		pdm.setNumComponents(2);

		for (int i = 0; i < 10; i++) {
			final double[] scaling = { uniform.nextDoubleFromTo(-2, 2), uniform.nextDoubleFromTo(-2, 2) };
			final PointList newShape = pdm.generateNewShape(scaling);
			final double[] predictedScaling = pdm.fitModel(newShape).secondObject();

			assertArrayEquals(scaling, predictedScaling, 0.01);
		}
	}
}
