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Diffstat (limited to 'src/main/java/org/apache/commons/math3/stat/descriptive/summary')
-rw-r--r--src/main/java/org/apache/commons/math3/stat/descriptive/summary/Product.java230
-rw-r--r--src/main/java/org/apache/commons/math3/stat/descriptive/summary/Sum.java226
-rw-r--r--src/main/java/org/apache/commons/math3/stat/descriptive/summary/SumOfLogs.java170
-rw-r--r--src/main/java/org/apache/commons/math3/stat/descriptive/summary/SumOfSquares.java159
-rw-r--r--src/main/java/org/apache/commons/math3/stat/descriptive/summary/package-info.java20
5 files changed, 805 insertions, 0 deletions
diff --git a/src/main/java/org/apache/commons/math3/stat/descriptive/summary/Product.java b/src/main/java/org/apache/commons/math3/stat/descriptive/summary/Product.java
new file mode 100644
index 0000000..7d313a5
--- /dev/null
+++ b/src/main/java/org/apache/commons/math3/stat/descriptive/summary/Product.java
@@ -0,0 +1,230 @@
+/*
+ * 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.stat.descriptive.WeightedEvaluation;
+import org.apache.commons.math3.util.FastMath;
+import org.apache.commons.math3.util.MathUtils;
+
+/**
+ * Returns the product of the available values.
+ * <p>
+ * If there are no values in the dataset, then 1 is returned.
+ * If any of the values are
+ * <code>NaN</code>, then <code>NaN</code> is returned.</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 Product extends AbstractStorelessUnivariateStatistic implements Serializable, WeightedEvaluation {
+
+ /** Serializable version identifier */
+ private static final long serialVersionUID = 2824226005990582538L;
+
+ /**The number of values that have been added */
+ private long n;
+
+ /**
+ * The current Running Product.
+ */
+ private double value;
+
+ /**
+ * Create a Product instance
+ */
+ public Product() {
+ n = 0;
+ value = 1;
+ }
+
+ /**
+ * Copy constructor, creates a new {@code Product} identical
+ * to the {@code original}
+ *
+ * @param original the {@code Product} instance to copy
+ * @throws NullArgumentException if original is null
+ */
+ public Product(Product original) throws NullArgumentException {
+ copy(original, this);
+ }
+
+ /**
+ * {@inheritDoc}
+ */
+ @Override
+ public void increment(final double d) {
+ value *= d;
+ n++;
+ }
+
+ /**
+ * {@inheritDoc}
+ */
+ @Override
+ public double getResult() {
+ return value;
+ }
+
+ /**
+ * {@inheritDoc}
+ */
+ public long getN() {
+ return n;
+ }
+
+ /**
+ * {@inheritDoc}
+ */
+ @Override
+ public void clear() {
+ value = 1;
+ n = 0;
+ }
+
+ /**
+ * Returns the product 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>
+ *
+ * @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 product of the values or 1 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 product = Double.NaN;
+ if (test(values, begin, length, true)) {
+ product = 1.0;
+ for (int i = begin; i < begin + length; i++) {
+ product *= values[i];
+ }
+ }
+ return product;
+ }
+
+ /**
+ * <p>Returns the weighted product of the entries in the specified portion of
+ * the input array, or <code>Double.NaN</code> if the designated subarray
+ * is empty.</p>
+ *
+ * <p>Throws <code>MathIllegalArgumentException</code> if any of the following are true:
+ * <ul><li>the values array is null</li>
+ * <li>the weights array is null</li>
+ * <li>the weights array does not have the same length as the values array</li>
+ * <li>the weights array contains one or more infinite values</li>
+ * <li>the weights array contains one or more NaN values</li>
+ * <li>the weights array contains negative values</li>
+ * <li>the start and length arguments do not determine a valid array</li>
+ * </ul></p>
+ *
+ * <p>Uses the formula, <pre>
+ * weighted product = &prod;values[i]<sup>weights[i]</sup>
+ * </pre>
+ * that is, the weights are applied as exponents when computing the weighted product.</p>
+ *
+ * @param values the input array
+ * @param weights the weights array
+ * @param begin index of the first array element to include
+ * @param length the number of elements to include
+ * @return the product of the values or 1 if length = 0
+ * @throws MathIllegalArgumentException if the parameters are not valid
+ * @since 2.1
+ */
+ public double evaluate(final double[] values, final double[] weights,
+ final int begin, final int length) throws MathIllegalArgumentException {
+ double product = Double.NaN;
+ if (test(values, weights, begin, length, true)) {
+ product = 1.0;
+ for (int i = begin; i < begin + length; i++) {
+ product *= FastMath.pow(values[i], weights[i]);
+ }
+ }
+ return product;
+ }
+
+ /**
+ * <p>Returns the weighted product of the entries in the input array.</p>
+ *
+ * <p>Throws <code>MathIllegalArgumentException</code> if any of the following are true:
+ * <ul><li>the values array is null</li>
+ * <li>the weights array is null</li>
+ * <li>the weights array does not have the same length as the values array</li>
+ * <li>the weights array contains one or more infinite values</li>
+ * <li>the weights array contains one or more NaN values</li>
+ * <li>the weights array contains negative values</li>
+ * </ul></p>
+ *
+ * <p>Uses the formula, <pre>
+ * weighted product = &prod;values[i]<sup>weights[i]</sup>
+ * </pre>
+ * that is, the weights are applied as exponents when computing the weighted product.</p>
+ *
+ * @param values the input array
+ * @param weights the weights array
+ * @return the product of the values or Double.NaN if length = 0
+ * @throws MathIllegalArgumentException if the parameters are not valid
+ * @since 2.1
+ */
+ public double evaluate(final double[] values, final double[] weights)
+ throws MathIllegalArgumentException {
+ return evaluate(values, weights, 0, values.length);
+ }
+
+
+ /**
+ * {@inheritDoc}
+ */
+ @Override
+ public Product copy() {
+ Product result = new Product();
+ // No try-catch or advertised exception because args are valid
+ copy(this, result);
+ return result;
+ }
+
+ /**
+ * Copies source to dest.
+ * <p>Neither source nor dest can be null.</p>
+ *
+ * @param source Product to copy
+ * @param dest Product to copy to
+ * @throws NullArgumentException if either source or dest is null
+ */
+ public static void copy(Product source, Product dest)
+ throws NullArgumentException {
+ MathUtils.checkNotNull(source);
+ MathUtils.checkNotNull(dest);
+ dest.setData(source.getDataRef());
+ dest.n = source.n;
+ dest.value = source.value;
+ }
+
+}
diff --git a/src/main/java/org/apache/commons/math3/stat/descriptive/summary/Sum.java b/src/main/java/org/apache/commons/math3/stat/descriptive/summary/Sum.java
new file mode 100644
index 0000000..e12b6a1
--- /dev/null
+++ b/src/main/java/org/apache/commons/math3/stat/descriptive/summary/Sum.java
@@ -0,0 +1,226 @@
+/*
+ * 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.MathUtils;
+
+
+/**
+ * Returns the sum of the available values.
+ * <p>
+ * If there are no values in the dataset, then 0 is returned.
+ * If any of the values are
+ * <code>NaN</code>, then <code>NaN</code> is returned.</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 Sum extends AbstractStorelessUnivariateStatistic implements Serializable {
+
+ /** Serializable version identifier */
+ private static final long serialVersionUID = -8231831954703408316L;
+
+ /** */
+ private long n;
+
+ /**
+ * The currently running sum.
+ */
+ private double value;
+
+ /**
+ * Create a Sum instance
+ */
+ public Sum() {
+ n = 0;
+ value = 0;
+ }
+
+ /**
+ * Copy constructor, creates a new {@code Sum} identical
+ * to the {@code original}
+ *
+ * @param original the {@code Sum} instance to copy
+ * @throws NullArgumentException if original is null
+ */
+ public Sum(Sum original) throws NullArgumentException {
+ copy(original, this);
+ }
+
+ /**
+ * {@inheritDoc}
+ */
+ @Override
+ public void increment(final double d) {
+ value += d;
+ n++;
+ }
+
+ /**
+ * {@inheritDoc}
+ */
+ @Override
+ public double getResult() {
+ return value;
+ }
+
+ /**
+ * {@inheritDoc}
+ */
+ public long getN() {
+ return n;
+ }
+
+ /**
+ * {@inheritDoc}
+ */
+ @Override
+ public void clear() {
+ value = 0;
+ n = 0;
+ }
+
+ /**
+ * The sum of the entries in the specified portion of
+ * the input array, or 0 if the designated subarray
+ * is empty.
+ * <p>
+ * Throws <code>MathIllegalArgumentException</code> if the array is null.</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 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 sum = Double.NaN;
+ if (test(values, begin, length, true)) {
+ sum = 0.0;
+ for (int i = begin; i < begin + length; i++) {
+ sum += values[i];
+ }
+ }
+ return sum;
+ }
+
+ /**
+ * The weighted sum of the entries in the specified portion of
+ * the input array, or 0 if the designated subarray
+ * is empty.
+ * <p>
+ * Throws <code>MathIllegalArgumentException</code> if any of the following are true:
+ * <ul><li>the values array is null</li>
+ * <li>the weights array is null</li>
+ * <li>the weights array does not have the same length as the values array</li>
+ * <li>the weights array contains one or more infinite values</li>
+ * <li>the weights array contains one or more NaN values</li>
+ * <li>the weights array contains negative values</li>
+ * <li>the start and length arguments do not determine a valid array</li>
+ * </ul></p>
+ * <p>
+ * Uses the formula, <pre>
+ * weighted sum = &Sigma;(values[i] * weights[i])
+ * </pre></p>
+ *
+ * @param values the input array
+ * @param weights the weights array
+ * @param begin index of the first array element to include
+ * @param length the number of elements to include
+ * @return the sum of the values or 0 if length = 0
+ * @throws MathIllegalArgumentException if the parameters are not valid
+ * @since 2.1
+ */
+ public double evaluate(final double[] values, final double[] weights,
+ final int begin, final int length) throws MathIllegalArgumentException {
+ double sum = Double.NaN;
+ if (test(values, weights, begin, length, true)) {
+ sum = 0.0;
+ for (int i = begin; i < begin + length; i++) {
+ sum += values[i] * weights[i];
+ }
+ }
+ return sum;
+ }
+
+ /**
+ * The weighted sum of the entries in the the input array.
+ * <p>
+ * Throws <code>MathIllegalArgumentException</code> if any of the following are true:
+ * <ul><li>the values array is null</li>
+ * <li>the weights array is null</li>
+ * <li>the weights array does not have the same length as the values array</li>
+ * <li>the weights array contains one or more infinite values</li>
+ * <li>the weights array contains one or more NaN values</li>
+ * <li>the weights array contains negative values</li>
+ * </ul></p>
+ * <p>
+ * Uses the formula, <pre>
+ * weighted sum = &Sigma;(values[i] * weights[i])
+ * </pre></p>
+ *
+ * @param values the input array
+ * @param weights the weights array
+ * @return the sum of the values or Double.NaN if length = 0
+ * @throws MathIllegalArgumentException if the parameters are not valid
+ * @since 2.1
+ */
+ public double evaluate(final double[] values, final double[] weights)
+ throws MathIllegalArgumentException {
+ return evaluate(values, weights, 0, values.length);
+ }
+
+ /**
+ * {@inheritDoc}
+ */
+ @Override
+ public Sum copy() {
+ Sum result = new Sum();
+ // No try-catch or advertised exception because args are valid
+ copy(this, result);
+ return result;
+ }
+
+ /**
+ * Copies source to dest.
+ * <p>Neither source nor dest can be null.</p>
+ *
+ * @param source Sum to copy
+ * @param dest Sum to copy to
+ * @throws NullArgumentException if either source or dest is null
+ */
+ public static void copy(Sum source, Sum dest)
+ throws NullArgumentException {
+ MathUtils.checkNotNull(source);
+ MathUtils.checkNotNull(dest);
+ dest.setData(source.getDataRef());
+ dest.n = source.n;
+ dest.value = source.value;
+ }
+
+}
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
new file mode 100644
index 0000000..19718af
--- /dev/null
+++ b/src/main/java/org/apache/commons/math3/stat/descriptive/summary/SumOfLogs.java
@@ -0,0 +1,170 @@
+/*
+ * 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;
+ }
+}
diff --git a/src/main/java/org/apache/commons/math3/stat/descriptive/summary/SumOfSquares.java b/src/main/java/org/apache/commons/math3/stat/descriptive/summary/SumOfSquares.java
new file mode 100644
index 0000000..161d8c8
--- /dev/null
+++ b/src/main/java/org/apache/commons/math3/stat/descriptive/summary/SumOfSquares.java
@@ -0,0 +1,159 @@
+/*
+ * 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.MathUtils;
+
+/**
+ * Returns the sum of the squares of the available values.
+ * <p>
+ * If there are no values in the dataset, then 0 is returned.
+ * If any of the values are
+ * <code>NaN</code>, then <code>NaN</code> is returned.</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 SumOfSquares extends AbstractStorelessUnivariateStatistic implements Serializable {
+
+ /** Serializable version identifier */
+ private static final long serialVersionUID = 1460986908574398008L;
+
+ /** */
+ private long n;
+
+ /**
+ * The currently running sumSq
+ */
+ private double value;
+
+ /**
+ * Create a SumOfSquares instance
+ */
+ public SumOfSquares() {
+ n = 0;
+ value = 0;
+ }
+
+ /**
+ * Copy constructor, creates a new {@code SumOfSquares} identical
+ * to the {@code original}
+ *
+ * @param original the {@code SumOfSquares} instance to copy
+ * @throws NullArgumentException if original is null
+ */
+ public SumOfSquares(SumOfSquares original) throws NullArgumentException {
+ copy(original, this);
+ }
+
+ /**
+ * {@inheritDoc}
+ */
+ @Override
+ public void increment(final double d) {
+ value += d * d;
+ n++;
+ }
+
+ /**
+ * {@inheritDoc}
+ */
+ @Override
+ public double getResult() {
+ return value;
+ }
+
+ /**
+ * {@inheritDoc}
+ */
+ public long getN() {
+ return n;
+ }
+
+ /**
+ * {@inheritDoc}
+ */
+ @Override
+ public void clear() {
+ value = 0;
+ n = 0;
+ }
+
+ /**
+ * Returns the sum of the squares 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>
+ *
+ * @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 squares 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 sumSq = Double.NaN;
+ if (test(values, begin, length, true)) {
+ sumSq = 0.0;
+ for (int i = begin; i < begin + length; i++) {
+ sumSq += values[i] * values[i];
+ }
+ }
+ return sumSq;
+ }
+
+ /**
+ * {@inheritDoc}
+ */
+ @Override
+ public SumOfSquares copy() {
+ SumOfSquares result = new SumOfSquares();
+ // 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 SumOfSquares to copy
+ * @param dest SumOfSquares to copy to
+ * @throws NullArgumentException if either source or dest is null
+ */
+ public static void copy(SumOfSquares source, SumOfSquares dest)
+ throws NullArgumentException {
+ MathUtils.checkNotNull(source);
+ MathUtils.checkNotNull(dest);
+ dest.setData(source.getDataRef());
+ dest.n = source.n;
+ dest.value = source.value;
+ }
+
+}
diff --git a/src/main/java/org/apache/commons/math3/stat/descriptive/summary/package-info.java b/src/main/java/org/apache/commons/math3/stat/descriptive/summary/package-info.java
new file mode 100644
index 0000000..2f07145
--- /dev/null
+++ b/src/main/java/org/apache/commons/math3/stat/descriptive/summary/package-info.java
@@ -0,0 +1,20 @@
+/*
+ * 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.
+ */
+/**
+ * Other summary statistics.
+ */
+package org.apache.commons.math3.stat.descriptive.summary;