implement ReplayFile mean and variance calculation + some tests

tools.descartes.dml.mm.applicationlevel/src/tools/descartes/dml/mm/applicationlevel/functions/util/RandomVariableHelper.java

 package tools.descartes.dml.mm.applicationlevel.functions.util;
 
+import java.io.BufferedReader;
+import java.io.FileReader;
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.List;
+
 import org.apache.commons.math3.distribution.EnumeratedIntegerDistribution;
 import org.apache.commons.math3.distribution.EnumeratedRealDistribution;
 
@@ -71,6 +78,19 @@ public class RandomVariableHelper {
 		return _getNumericalVariance(probfn);
 	}
 
+	private static Double _getNumericalVariance(ReplayFile replay) {
+		double variance = 0;
+		try {
+			Collection<Double> samples = collectSamples(replay);
+			double mean = _getNumericalMean(samples);
+			variance = samples.parallelStream().mapToDouble(sample -> Math.pow(sample, 2)).average().getAsDouble()
+					- Math.pow(mean, 2);
+		} catch (IOException e) {
+			e.printStackTrace();
+		}
+		return variance;
+	}
+
 	private static Double _getNumericalVariance(EnumSampleList enumSl) {
 		throw new UnsupportedOperationException("Enums do not have a numerical variance.");
 	}
@@ -158,8 +178,14 @@ public class RandomVariableHelper {
 	}
 
 	private static Double _getNumericalMean(ReplayFile replay) {
-		double sum = 0;
-		throw new UnsupportedOperationException("File Path: " + replay.getFilepath());
+		double mean = 0;
+		try {
+			mean = _getNumericalMean(collectSamples(replay));
+		} catch (IOException e) {
+			// TODO consult for proper error handling
+			e.printStackTrace();
+		}
+		return mean;
 	}
 
 	private static Double _getNumericalMean(ProbabilityMassFunction pmf) {
@@ -246,4 +272,17 @@ public class RandomVariableHelper {
 		throw new IllegalStateException("Unknown type of ProbabilityFunction: " + probfn.getClass().getName());
 	}
 
+	private static Collection<Double> collectSamples(ReplayFile replay) throws IOException {
+		List<Double> samples = new ArrayList<Double>();
+		BufferedReader br = new BufferedReader(new FileReader(replay.getFilepath()));
+		while (br.ready()) {
+			samples.add(Double.parseDouble(br.readLine()));
+		}
+		br.close();
+		return samples;
+	}
+
+	private static Double _getNumericalMean(Collection<Double> samples) {
+		return samples.parallelStream().mapToDouble(sample -> sample).average().getAsDouble();
+	}
 }

tools.descartes.dml.mm.applicationlevel/src/tools/descartes/dml/mm/applicationlevel/functions/util/tests/ReplayMeanTest.java

+package tools.descartes.dml.mm.applicationlevel.functions.util.tests;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+import tools.descartes.dml.mm.applicationlevel.functions.RandomVariable;
+import tools.descartes.dml.mm.applicationlevel.functions.util.RandomVariableHelper;
+
+public class ReplayMeanTest extends AbstractRandomVariableHelperTest {
+
+	@Test
+	public void replayFileUnaryTest() {
+		RandomVariable randomVariable = loadModel("testfiles/replay-unary.functions", RandomVariable.class);
+		Assert.assertEquals(10, RandomVariableHelper.getNumericalMean(randomVariable.getProbFunction()), 0.0001);
+	}
+
+	@Test
+	public void replayFileSequenceTest() {
+		RandomVariable randomVariable = loadModel("testfiles/replay-sequence.functions", RandomVariable.class);
+		Assert.assertEquals(-4.89, RandomVariableHelper.getNumericalMean(randomVariable.getProbFunction()), 0.01);
+	}
+}

tools.descartes.dml.mm.applicationlevel/src/tools/descartes/dml/mm/applicationlevel/functions/util/tests/ReplayVarianceTest.java

+package tools.descartes.dml.mm.applicationlevel.functions.util.tests;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+import tools.descartes.dml.mm.applicationlevel.functions.RandomVariable;
+import tools.descartes.dml.mm.applicationlevel.functions.util.RandomVariableHelper;
+
+public class ReplayVarianceTest extends AbstractRandomVariableHelperTest {
+
+	@Test
+	public void replayFileUnaryTest() {
+		RandomVariable randomVariable = loadModel("testfiles/replay-unary.functions", RandomVariable.class);
+		Assert.assertEquals(0, RandomVariableHelper.getNumericalVariance(randomVariable.getProbFunction()), 0.0001);
+	}
+
+	@Test
+	public void replayFileSequenceTest() {
+		RandomVariable randomVariable = loadModel("testfiles/replay-sequence.functions", RandomVariable.class);
+		Assert.assertEquals(3250.2379, RandomVariableHelper.getNumericalVariance(randomVariable.getProbFunction()),
+				0.0001);
+	}
+}

tools.descartes.dml.mm.applicationlevel/testfiles/replay-sequence.functions

+<?xml version="1.0" encoding="UTF-8"?>
+<functions:RandomVariable xmi:version="2.0" xmlns:xmi="http://www.omg.org/XMI" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:functions="http://www.descartes.tools/metamodel/functions/1.0">
+  <probFunction xsi:type="functions:ReplayFile" Filepath="/Users/longbui/Downloads/sequence.csv"/>
+</functions:RandomVariable>

tools.descartes.dml.mm.applicationlevel/testfiles/replay-unary.functions

+<?xml version="1.0" encoding="UTF-8"?>
+<functions:RandomVariable xmi:version="2.0" xmlns:xmi="http://www.omg.org/XMI" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:functions="http://www.descartes.tools/metamodel/functions/1.0">
+  <probFunction xsi:type="functions:ReplayFile" Filepath="/Users/longbui/Downloads/test.csv"/>
+</functions:RandomVariable>