/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.commons.math.stat.regression;

import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertTrue;

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

public abstract class MultipleLinearRegressionAbstractTest {

	protected MultipleLinearRegression regression;

	@Before
	public void setUp() {
		regression = createRegression();
	}

	protected abstract MultipleLinearRegression createRegression();

	protected abstract int getNumberOfRegressors();

	protected abstract int getSampleSize();

	@Test
	public void canEstimateRegressionParameters() {
		double[] beta = regression.estimateRegressionParameters();
		assertEquals(getNumberOfRegressors(), beta.length);
	}

	@Test
	public void canEstimateResiduals() {
		double[] e = regression.estimateResiduals();
		assertEquals(getSampleSize(), e.length);
	}

	@Test
	public void canEstimateRegressionParametersVariance() {
		double[][] variance = regression.estimateRegressionParametersVariance();
		assertEquals(getNumberOfRegressors(), variance.length);
	}

	@Test
	public void canEstimateRegressandVariance() {
		if (getSampleSize() > getNumberOfRegressors()) {
			double variance = regression.estimateRegressandVariance();
			assertTrue(variance > 0.0);
		}
	}

}
