Fixing GeoMean and adding appropriate test.

git-svn-id: https://svn.apache.org/repos/asf/jakarta/commons/proper/math/trunk@140972 13f79535-47bb-0310-9956-ffa450edef68

src/java/org/apache/commons/math/stat/univariate/moment/GeometricMean.java

@@ -53,18 +53,17 @@
  */
 package org.apache.commons.math.stat.univariate.moment;
 
-import org.apache.commons.math.stat.univariate.AbstractStorelessUnivariateStatistic;
 import org.apache.commons.math.stat.univariate.summary.SumOfLogs;
 
 /**
  * @author Mark Diggory
  *
  */
-public class GeometricMean extends AbstractStorelessUnivariateStatistic {
+public class GeometricMean extends SumOfLogs {
  
-    private SumOfLogs sumLog = new SumOfLogs();
+    //private SumOfLogs sumLog = new SumOfLogs();
     
-    private double value = Double.NaN;
+    private double geoMean = Double.NaN;
     
     private int n = 0;
     
@@ -73,22 +72,22 @@ public class GeometricMean extends AbstractStorelessUnivariateStatistic {
      */
     public double increment(double d) {
         n++;
-        return Math.exp( sumLog.increment(d) / (double)n );
+        return geoMean = Math.exp( super.increment(d) / (double)n );
     }
 
     /**
      * @see org.apache.commons.math.stat.univariate.StorelessUnivariateStatistic#getValue()
      */
     public double getValue() {
-        return value;
+        return geoMean;
     }
 
     /**
      * @see org.apache.commons.math.stat.univariate.StorelessUnivariateStatistic#clear()
      */
     public void clear() {
-        value = Double.NaN;
+        super.clear();
-        sumLog.clear();
+        geoMean = Double.NaN;
         n = 0;
     }
     
@@ -96,7 +95,7 @@ public class GeometricMean extends AbstractStorelessUnivariateStatistic {
      * @see org.apache.commons.math.stat.univariate.UnivariateStatistic#evaluate(double[], int, int)
      */
     public double evaluate(double[] values, int begin, int length) {
-        return Math.exp(sumLog.evaluate(values, begin, length) / (double) length );
+        return Math.exp(super.evaluate(values, begin, length) / (double) length );
     }
 
 

src/test/org/apache/commons/math/stat/univariate/moment/GeometricMeanTest.java

@@ -0,0 +1,103 @@
+/* ====================================================================
+ * The Apache Software License, Version 1.1
+ *
+ * Copyright (c) 2003 The Apache Software Foundation.  All rights
+ * reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *
+ * 2. 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.
+ *
+ * 3. The end-user documentation included with the redistribution, if
+ *    any, must include the following acknowlegement:
+ *       "This product includes software developed by the
+ *        Apache Software Foundation (http://www.apache.org/)."
+ *    Alternately, this acknowlegement may appear in the software itself,
+ *    if and wherever such third-party acknowlegements normally appear.
+ *
+ * 4. The names "The Jakarta Project", "Commons", and "Apache Software
+ *    Foundation" must not be used to endorse or promote products derived
+ *    from this software without prior written permission. For written
+ *    permission, please contact apache@apache.org.
+ *
+ * 5. Products derived from this software may not be called "Apache"
+ *    nor may "Apache" appear in their names without prior written
+ *    permission of the Apache Software Foundation.
+ *
+ * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED 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 APACHE SOFTWARE FOUNDATION OR
+ * ITS 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.
+ * ====================================================================
+ *
+ * This software consists of voluntary contributions made by many
+ * individuals on behalf of the Apache Software Foundation.  For more
+ * information on the Apache Software Foundation, please see
+ * <http://www.apache.org/>.
+ */
+package org.apache.commons.math.stat.univariate.moment;
+
+import junit.framework.Test;
+import junit.framework.TestSuite;
+
+import org.apache.commons.math.stat.univariate.StorelessUnivariateStatisticAbstractTest;
+import org.apache.commons.math.stat.univariate.UnivariateStatistic;
+import org.apache.commons.math.stat.univariate.UnivariateStatisticAbstractTest;
+
+/**
+ * Test cases for the {@link UnivariateStatistic} class.
+ *
+ * @author Mark Diggory
+ */
+public class GeometricMeanTest extends StorelessUnivariateStatisticAbstractTest{
+
+    protected GeometricMean stat;
+    
+    /**
+     * @param name
+     */
+    public GeometricMeanTest(String name) {
+        super(name);
+    }
+
+    public static Test suite() {
+        TestSuite suite = new TestSuite(GeometricMeanTest.class);
+        suite.setName("Mean  Tests");
+        return suite;
+    }
+    
+    /* (non-Javadoc)
+     * @see org.apache.commons.math.stat.univariate.UnivariateStatisticAbstractTest#getUnivariateStatistic()
+     */
+    public UnivariateStatistic getUnivariateStatistic() {
+       
+        if(stat == null)
+            stat = new GeometricMean();
+            
+        return stat;
+    }
+
+    /* (non-Javadoc)
+     * @see org.apache.commons.math.stat.univariate.UnivariateStatisticAbstractTest#expectedValue()
+     */
+    public double expectedValue() {
+        return this.geoMean;
+    }
+
+}