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diff --git a/src/main/java/org/apache/commons/math3/stat/descriptive/moment/GeometricMean.java b/src/main/java/org/apache/commons/math3/stat/descriptive/moment/GeometricMean.java
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+/*
+ * 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.math3.stat.descriptive.moment;
+
+import java.io.Serializable;
+
+import org.apache.commons.math3.exception.MathIllegalArgumentException;
+import org.apache.commons.math3.exception.MathIllegalStateException;
+import org.apache.commons.math3.exception.NullArgumentException;
+import org.apache.commons.math3.exception.util.LocalizedFormats;
+import org.apache.commons.math3.stat.descriptive.AbstractStorelessUnivariateStatistic;
+import org.apache.commons.math3.stat.descriptive.StorelessUnivariateStatistic;
+import org.apache.commons.math3.stat.descriptive.summary.SumOfLogs;
+import org.apache.commons.math3.util.FastMath;
+import org.apache.commons.math3.util.MathUtils;
+
+/**
+ * Returns the <a href="http://www.xycoon.com/geometric_mean.htm">
+ * geometric mean </a> of the available values.
+ * <p>
+ * Uses a {@link SumOfLogs} instance to compute sum of logs and returns
+ * <code> exp( 1/n  (sum of logs) ).</code>  Therefore, </p>
+ * <ul>
+ * <li>If any of values are < 0, the result is <code>NaN.</code></li>
+ * <li>If all values are non-negative and less than
+ * <code>Double.POSITIVE_INFINITY</code>,  but at least one value is 0, the
+ * result is <code>0.</code></li>
+ * <li>If both <code>Double.POSITIVE_INFINITY</code> and
+ * <code>Double.NEGATIVE_INFINITY</code> are among the values, the result is
+ * <code>NaN.</code></li>
+ * </ul> </p>
+ * <p>
+ * <strong>Note that this implementation is not synchronized.</strong> If
+ * multiple threads access an instance of this class concurrently, and at least
+ * one of the threads invokes the <code>increment()</code> or
+ * <code>clear()</code> method, it must be synchronized externally.</p>
+ *
+ *
+ */
+public class GeometricMean extends AbstractStorelessUnivariateStatistic implements Serializable {
+
+    /** Serializable version identifier */
+    private static final long serialVersionUID = -8178734905303459453L;
+
+    /** Wrapped SumOfLogs instance */
+    private StorelessUnivariateStatistic sumOfLogs;
+
+    /**
+     * Create a GeometricMean instance
+     */
+    public GeometricMean() {
+        sumOfLogs = new SumOfLogs();
+    }
+
+    /**
+     * Copy constructor, creates a new {@code GeometricMean} identical
+     * to the {@code original}
+     *
+     * @param original the {@code GeometricMean} instance to copy
+     * @throws NullArgumentException if original is null
+     */
+    public GeometricMean(GeometricMean original) throws NullArgumentException {
+        super();
+        copy(original, this);
+    }
+
+    /**
+     * Create a GeometricMean instance using the given SumOfLogs instance
+     * @param sumOfLogs sum of logs instance to use for computation
+     */
+    public GeometricMean(SumOfLogs sumOfLogs) {
+        this.sumOfLogs = sumOfLogs;
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    @Override
+    public GeometricMean copy() {
+        GeometricMean result = new GeometricMean();
+        // no try-catch or advertised exception because args guaranteed non-null
+        copy(this, result);
+        return result;
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    @Override
+    public void increment(final double d) {
+        sumOfLogs.increment(d);
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    @Override
+    public double getResult() {
+        if (sumOfLogs.getN() > 0) {
+            return FastMath.exp(sumOfLogs.getResult() / sumOfLogs.getN());
+        } else {
+            return Double.NaN;
+        }
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    @Override
+    public void clear() {
+        sumOfLogs.clear();
+    }
+
+    /**
+     * Returns the geometric mean of the entries in the specified portion
+     * of the input array.
+     * <p>
+     * See {@link GeometricMean} for details on the computing algorithm.</p>
+     * <p>
+     * Throws <code>IllegalArgumentException</code> if the array is null.</p>
+     *
+     * @param values input array containing the values
+     * @param begin first array element to include
+     * @param length the number of elements to include
+     * @return the geometric mean or Double.NaN if length = 0 or
+     * any of the values are &lt;= 0.
+     * @throws MathIllegalArgumentException if the input array is null or the array
+     * index parameters are not valid
+     */
+    @Override
+    public double evaluate(
+        final double[] values, final int begin, final int length)
+    throws MathIllegalArgumentException {
+        return FastMath.exp(
+            sumOfLogs.evaluate(values, begin, length) / length);
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public long getN() {
+        return sumOfLogs.getN();
+    }
+
+    /**
+     * <p>Sets the implementation for the sum of logs.</p>
+     * <p>This method must be activated before any data has been added - i.e.,
+     * before {@link #increment(double) increment} has been used to add data;
+     * otherwise an IllegalStateException will be thrown.</p>
+     *
+     * @param sumLogImpl the StorelessUnivariateStatistic instance to use
+     * for computing the log sum
+     * @throws MathIllegalStateException if data has already been added
+     *  (i.e if n > 0)
+     */
+    public void setSumLogImpl(StorelessUnivariateStatistic sumLogImpl)
+    throws MathIllegalStateException {
+        checkEmpty();
+        this.sumOfLogs = sumLogImpl;
+    }
+
+    /**
+     * Returns the currently configured sum of logs implementation
+     *
+     * @return the StorelessUnivariateStatistic implementing the log sum
+     */
+    public StorelessUnivariateStatistic getSumLogImpl() {
+        return sumOfLogs;
+    }
+
+    /**
+     * Copies source to dest.
+     * <p>Neither source nor dest can be null.</p>
+     *
+     * @param source GeometricMean to copy
+     * @param dest GeometricMean to copy to
+     * @throws NullArgumentException if either source or dest is null
+     */
+    public static void copy(GeometricMean source, GeometricMean dest)
+        throws NullArgumentException {
+        MathUtils.checkNotNull(source);
+        MathUtils.checkNotNull(dest);
+        dest.setData(source.getDataRef());
+        dest.sumOfLogs = source.sumOfLogs.copy();
+    }
+
+
+    /**
+     * Throws MathIllegalStateException if n > 0.
+     * @throws MathIllegalStateException if data has been added to this statistic
+     */
+    private void checkEmpty() throws MathIllegalStateException {
+        if (getN() > 0) {
+            throw new MathIllegalStateException(
+                    LocalizedFormats.VALUES_ADDED_BEFORE_CONFIGURING_STATISTIC,
+                    getN());
+        }
+    }
+
+}