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Posted to commits@commons.apache.org by kh...@apache.org on 2019/06/01 19:48:40 UTC

[commons-statistics] 01/01: [STATISTICS-14] - BigDecimalStatistics

This is an automated email from the ASF dual-hosted git repository.

khmarbaise pushed a commit to branch STATISTICS-14
in repository https://gitbox.apache.org/repos/asf/commons-statistics.git

commit 4e65221a692dbf8346d2ac9ca9958a6e879b4da5
Author: Karl Heinz Marbaise <kh...@apache.org>
AuthorDate: Sat Jun 1 21:45:41 2019 +0200

    [STATISTICS-14] - BigDecimalStatistics
---
 .../distribution/BigDecimalConsumer.java           |  31 +++
 .../distribution/BigDecimalSummaryStatistics.java  | 208 +++++++++++++++++++++
 .../BigDecimalSummaryStatisticsTest.java           |  59 ++++++
 3 files changed, 298 insertions(+)

diff --git a/commons-statistics-distribution/src/main/java/org/apache/commons/statistics/distribution/BigDecimalConsumer.java b/commons-statistics-distribution/src/main/java/org/apache/commons/statistics/distribution/BigDecimalConsumer.java
new file mode 100644
index 0000000..51da71e
--- /dev/null
+++ b/commons-statistics-distribution/src/main/java/org/apache/commons/statistics/distribution/BigDecimalConsumer.java
@@ -0,0 +1,31 @@
+/*
+ * 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.statistics.distribution;
+
+import java.math.BigDecimal;
+
+@FunctionalInterface
+public interface BigDecimalConsumer {
+
+    /**
+     * Performs this operation on the given argument.
+     *
+     * @param value the input argument
+     */
+    void accept(BigDecimal value);
+
+}
diff --git a/commons-statistics-distribution/src/main/java/org/apache/commons/statistics/distribution/BigDecimalSummaryStatistics.java b/commons-statistics-distribution/src/main/java/org/apache/commons/statistics/distribution/BigDecimalSummaryStatistics.java
new file mode 100644
index 0000000..0a51329
--- /dev/null
+++ b/commons-statistics-distribution/src/main/java/org/apache/commons/statistics/distribution/BigDecimalSummaryStatistics.java
@@ -0,0 +1,208 @@
+/*
+ * 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.statistics.distribution;
+
+import java.math.BigDecimal;
+
+/**
+ * Implementation for BigDecimalSummaryStatistics based on {@link java.util.DoubleSummaryStatistics}.
+ */
+public class BigDecimalSummaryStatistics implements BigDecimalConsumer {
+
+    /**
+     * internal counter.
+     */
+    private Long count;
+    /**
+     * The total.
+     */
+    private BigDecimal sum;
+    /**
+     * The minimum.
+     */
+    private BigDecimal min;
+    /**
+     * The maximum.
+     */
+    private BigDecimal max;
+
+    /**
+     * Create an instance of BigDecimalSummaryStatistics. {@code count = 0} and sum = {@link
+     * BigDecimal#ZERO}
+     */
+    public BigDecimalSummaryStatistics() {
+        this.count = Long.valueOf(0L);
+        this.sum = BigDecimal.ZERO;
+        this.max = null;
+        this.min = null;
+    }
+
+    /**
+     * Constructs a non-empty instance with the specified {@code count}, {@code min}, {@code max},
+     * and {@code sum}.
+     *
+     * <p>If {@code count} is zero then the remaining arguments are ignored and
+     * an empty instance is constructed.
+     *
+     * <p>If the arguments are inconsistent then an {@code IllegalArgumentException}
+     * is thrown.  The necessary consistent argument conditions are:
+     * <ul>
+     * <li>{@code count >= 0}</li>
+     * <li>{@code min <= max}</li>
+     * </ul>
+     *
+     * @param count the count of values
+     * @param min the minimum value
+     * @param max the maximum value
+     * @param sum the sum of all values
+     * @throws IllegalArgumentException if the arguments are inconsistent
+     */
+    public BigDecimalSummaryStatistics(Long count, BigDecimal min, BigDecimal max,
+        BigDecimal sum) throws IllegalArgumentException {
+        // FIXME: check for null in count, max, min, sum!
+        this.count = count;
+        this.sum = sum;
+        this.min = min;
+        this.max = max;
+        if (count < 0L) {
+            throw new IllegalArgumentException("Negative count value");
+        } else if (count > 0L) {
+            if (min.compareTo(max) > 0) {
+                throw new IllegalArgumentException("Minimum greater than maximum");
+            }
+
+            this.count = count;
+            this.sum = sum;
+            this.min = min;
+            this.max = max;
+        }
+    }
+
+    /**
+     * Records a new {@code BigDecimal} value into the summary information.
+     *
+     * @param value the input value
+     */
+    @Override
+    public void accept(BigDecimal value) {
+        count++;
+        sum = sum.add(value);
+
+        min = min == null ? value : min.min(value);
+        max = max == null ? value : max.max(value);
+    }
+
+    /**
+     * Combines the state of another {@code BigDecimalSummaryStatistics} into this one.
+     *
+     * @param other another {@code LongSummaryStatistics}
+     * @throws IllegalArgumentException if {@code other} is null
+     */
+    public void combine(BigDecimalSummaryStatistics other) throws IllegalArgumentException {
+        if (other == null) {
+            throw new IllegalArgumentException("other is not allowed to be null.");
+        }
+
+        count++;
+        sum = sum.add(other.sum);
+
+        min = min == null ? other.min : min.min(other.min);
+        max = max == null ? other.max : max.max(other.max);
+    }
+
+    /**
+     * Returns the count of values recorded.
+     *
+     * @return the count of values
+     */
+    public final Long getCount() {
+        return count;
+    }
+
+    /**
+     * Returns the sum of values recorded, or zero if no values have been recorded.
+     *
+     * @return the sum of values, or zero if none
+     */
+    public final BigDecimal getSum() {
+        return sum;
+    }
+
+    /**
+     * Returns the minimum value recorded, or {@code ??????} if no values have been recorded.
+     *
+     * @return the minimum value, or {@link BigDecimal#???} if none
+     * FIXME: What to do if no call of accept/combine has happened yet?
+     */
+    public final BigDecimal getMin() {
+        if (min == null) {
+            //TODO: Think about this!
+            return BigDecimal.valueOf(Double.NEGATIVE_INFINITY);
+        } else {
+            return min;
+        }
+    }
+
+    /**
+     * Returns the maximum value recorded, or {@code XXXX} if no values have been recorded.
+     *
+     * @return the maximum value, or {@code XXXX} if none
+     * FIXME: What to do if no call of accept/combine has happened yet?
+     */
+    public final BigDecimal getMax() {
+        if (max == null) {
+            //TODO: Think about this!
+            return BigDecimal.valueOf(Double.POSITIVE_INFINITY);
+        } else {
+            return max;
+        }
+    }
+
+    /**
+     * Returns the arithmetic mean of values recorded, or zero if no values have been recorded.
+     *
+     * @return The arithmetic mean of values, or zero if none
+     */
+    public final BigDecimal getAverage() {
+        if (getCount() > 0) {
+            BigDecimal bsum = getSum();
+            Long bcount = getCount();
+            return bsum.divide(BigDecimal.valueOf(bcount));
+        } else {
+            return BigDecimal.ZERO;
+        }
+    }
+
+    /**
+     * Returns a non-empty string representation of this object suitable for debugging. The exact
+     * presentation format is unspecified and may vary between implementations and versions.
+     */
+    @Override
+    public String toString() {
+        return String.format(
+            "%s{count=%s, sum=%s, min=%s, average=%s, max=%s}",
+            this.getClass()
+                .getSimpleName(),
+            getCount().toString(),
+            getSum().toString(),
+            getMin().toString(),
+            getAverage().toString(),
+            getMax().toString()
+        );
+    }
+
+}
diff --git a/commons-statistics-distribution/src/test/java/org/apache/commons/statistics/distribution/BigDecimalSummaryStatisticsTest.java b/commons-statistics-distribution/src/test/java/org/apache/commons/statistics/distribution/BigDecimalSummaryStatisticsTest.java
new file mode 100644
index 0000000..e39e067
--- /dev/null
+++ b/commons-statistics-distribution/src/test/java/org/apache/commons/statistics/distribution/BigDecimalSummaryStatisticsTest.java
@@ -0,0 +1,59 @@
+/*
+ * 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.statistics.distribution;
+
+import java.math.BigDecimal;
+import java.util.stream.LongStream;
+import org.junit.Assert;
+import org.junit.Test;
+
+/**
+ * The Unit Test for {@link BigDecimalSummaryStatistics}.
+ */
+public class BigDecimalSummaryStatisticsTest {
+
+    private static final double EPSILON = 1E-15d;
+
+    @Test
+    public void theFirstTenElementsShouldCombinedIntoTotal() {
+        BigDecimalSummaryStatistics collect =
+            LongStream.rangeClosed(1, 10)
+                .mapToObj(BigDecimal::valueOf)
+                .collect(BigDecimalSummaryStatistics::new,
+                    BigDecimalSummaryStatistics::accept,
+                    BigDecimalSummaryStatistics::combine);
+
+        Assert.assertEquals(5.5d, collect.getAverage().doubleValue(), EPSILON);
+        Assert.assertEquals(55d, collect.getSum().doubleValue(), EPSILON);
+        Assert.assertEquals(10L, collect.getCount().longValue());
+        Assert.assertEquals(1L, collect.getMin().longValue());
+        Assert.assertEquals(10L, collect.getMax().longValue());
+    }
+
+    @Test
+    public void standardDeviationBigDecimal() {
+        BigDecimalSummaryStatistics collect =
+            LongStream.rangeClosed(10, 2_000_000)
+                .mapToObj(BigDecimal::valueOf)
+                .collect(BigDecimalSummaryStatistics::new,
+                    BigDecimalSummaryStatistics::accept,
+                    BigDecimalSummaryStatistics::combine);
+        System.out.println("Collect:" + collect);
+    }
+
+
+}