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diff --git a/src/main/java/org/apache/commons/math3/stat/descriptive/summary/SumOfLogs.java b/src/main/java/org/apache/commons/math3/stat/descriptive/summary/SumOfLogs.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.summary;
+
+import java.io.Serializable;
+
+import org.apache.commons.math3.exception.MathIllegalArgumentException;
+import org.apache.commons.math3.exception.NullArgumentException;
+import org.apache.commons.math3.stat.descriptive.AbstractStorelessUnivariateStatistic;
+import org.apache.commons.math3.util.FastMath;
+import org.apache.commons.math3.util.MathUtils;
+
+/**
+ * Returns the sum of the natural logs for this collection of values.
+ * <p>
+ * Uses {@link org.apache.commons.math3.util.FastMath#log(double)} to compute the logs.
+ * Therefore,
+ * <ul>
+ * <li>If any of values are &lt; 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>Double.NEGATIVE_INFINITY.</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 SumOfLogs extends AbstractStorelessUnivariateStatistic implements Serializable {
+
+    /** Serializable version identifier */
+    private static final long serialVersionUID = -370076995648386763L;
+
+    /**Number of values that have been added */
+    private int n;
+
+    /**
+     * The currently running value
+     */
+    private double value;
+
+    /**
+     * Create a SumOfLogs instance
+     */
+    public SumOfLogs() {
+       value = 0d;
+       n = 0;
+    }
+
+    /**
+     * Copy constructor, creates a new {@code SumOfLogs} identical
+     * to the {@code original}
+     *
+     * @param original the {@code SumOfLogs} instance to copy
+     * @throws NullArgumentException if original is null
+     */
+    public SumOfLogs(SumOfLogs original) throws NullArgumentException {
+        copy(original, this);
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    @Override
+    public void increment(final double d) {
+        value += FastMath.log(d);
+        n++;
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    @Override
+    public double getResult() {
+        return value;
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public long getN() {
+        return n;
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    @Override
+    public void clear() {
+        value = 0d;
+        n = 0;
+    }
+
+    /**
+     * Returns the sum of the natural logs of the entries in the specified portion of
+     * the input array, or <code>Double.NaN</code> if the designated subarray
+     * is empty.
+     * <p>
+     * Throws <code>MathIllegalArgumentException</code> if the array is null.</p>
+     * <p>
+     * See {@link SumOfLogs}.</p>
+     *
+     * @param values the input array
+     * @param begin index of the first array element to include
+     * @param length the number of elements to include
+     * @return the sum of the natural logs of the values or 0 if
+     * length = 0
+     * @throws MathIllegalArgumentException if the 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 {
+        double sumLog = Double.NaN;
+        if (test(values, begin, length, true)) {
+            sumLog = 0.0;
+            for (int i = begin; i < begin + length; i++) {
+                sumLog += FastMath.log(values[i]);
+            }
+        }
+        return sumLog;
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    @Override
+    public SumOfLogs copy() {
+        SumOfLogs result = new SumOfLogs();
+        // No try-catch or advertised exception here because args are valid
+        copy(this, result);
+        return result;
+    }
+
+    /**
+     * Copies source to dest.
+     * <p>Neither source nor dest can be null.</p>
+     *
+     * @param source SumOfLogs to copy
+     * @param dest SumOfLogs to copy to
+     * @throws NullArgumentException if either source or dest is null
+     */
+    public static void copy(SumOfLogs source, SumOfLogs dest)
+        throws NullArgumentException {
+        MathUtils.checkNotNull(source);
+        MathUtils.checkNotNull(dest);
+        dest.setData(source.getDataRef());
+        dest.n = source.n;
+        dest.value = source.value;
+    }
+}