Java tutorial
/******************************************************************************* * Copyright 2012 the original author or authors. * * Licensed 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 emlab.util; import static org.junit.Assert.*; import org.apache.commons.math.stat.regression.SimpleRegression; import org.apache.log4j.Logger; import org.junit.Before; import org.junit.Test; import org.junit.runner.RunWith; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.data.neo4j.template.Neo4jOperations; import org.springframework.test.context.ContextConfiguration; import org.springframework.test.context.junit4.SpringJUnit4ClassRunner; import org.springframework.transaction.annotation.Transactional; import emlab.domain.market.ClearingPoint; import emlab.domain.market.CommodityMarket; import emlab.domain.technology.Substance; import emlab.repository.ClearingPointRepository; import emlab.util.GeometricTrendRegression; @RunWith(SpringJUnit4ClassRunner.class) @ContextConfiguration({ "/emlab-test-context.xml" }) @Transactional public class GeometricTrendRegressionTest { Logger logger = Logger.getLogger(GeometricTrendRegressionTest.class); @Autowired Neo4jOperations template; @Autowired ClearingPointRepository clearingPointRepository; @Before @Transactional public void setUp() throws Exception { } @Test public void testLinearTrendEstimation() { double[][] input = { { 0, 1 }, { 1, 1.1 }, { 2, 1.2 }, { 3, 1.3 }, { 4, 1.4 } }; double[] predictionYears = { 5, 6, 7, 8 }; double[] expectedResults = { 1.5, 1.6, 1.7, 1.8 }; SimpleRegression sr = new SimpleRegression(); sr.addData(input); for (int i = 0; i < predictionYears.length; i++) { assert (expectedResults[i] == sr.predict(predictionYears[i])); } } @Test public void testGeometricTrendEstimation() { double[][] input = { { 0, 1 }, { 1, 1.1 }, { 2, 1.21 }, { 3, 1.331 }, { 4, 1.4641 } }; double[] predictionYears = { 5, 6, 7, 8 }; double[] expectedResults = { 1.61051, 1.771561, 1.9487171, 2.14358881 }; GeometricTrendRegression gtr = new GeometricTrendRegression(); gtr.addData(input); for (int i = 0; i < predictionYears.length; i++) { assert (expectedResults[i] == gtr.predict(predictionYears[i])); } } @Test public void testGeometricTrendEstimationFromQuery() { double[][] input = { { 0, 1 }, { 1, 1.1 }, { 2, 1.21 }, { 3, 1.331 }, { 4, 1.4641 } }; Substance substance = new Substance(); substance.persist(); CommodityMarket market = new CommodityMarket(); market.setSubstance(substance); market.persist(); for (double[] d : input) { ClearingPoint cp = new ClearingPoint(); cp.setTime((long) d[0]); cp.setPrice(d[1]); cp.setAbstractMarket(market); template.save(cp); } Iterable<ClearingPoint> cps = clearingPointRepository .findAllClearingPointsForSubstanceAndTimeRange(substance, 0, 4); GeometricTrendRegression gtr = new GeometricTrendRegression(); for (ClearingPoint clearingPoint : cps) { gtr.addData(clearingPoint.getTime(), clearingPoint.getPrice()); } double[] predictionYears = { 5, 6, 7, 8 }; double[] expectedResults = { 1.61051, 1.771561, 1.9487171, 2.14358881 }; for (int i = 0; i < predictionYears.length; i++) { assert (expectedResults[i] == gtr.predict(predictionYears[i])); } } }