commons-commits mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From er...@apache.org
Subject [11/31] commons-numbers git commit: Multimodule project setup.
Date Fri, 20 Jan 2017 14:45:58 GMT
http://git-wip-us.apache.org/repos/asf/commons-numbers/blob/c4541327/commons-numbers-complex/src/test/java/org/apache/commons/numbers/complex/TestUtils.java
----------------------------------------------------------------------
diff --git a/commons-numbers-complex/src/test/java/org/apache/commons/numbers/complex/TestUtils.java b/commons-numbers-complex/src/test/java/org/apache/commons/numbers/complex/TestUtils.java
new file mode 100644
index 0000000..70dc4c1
--- /dev/null
+++ b/commons-numbers-complex/src/test/java/org/apache/commons/numbers/complex/TestUtils.java
@@ -0,0 +1,409 @@
+/*
+ * 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.numbers.complex;
+
+import java.io.ByteArrayInputStream;
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.io.ObjectInputStream;
+import java.io.ObjectOutputStream;
+
+import org.apache.commons.numbers.complex.Complex;
+
+import org.junit.Assert;
+
+/**
+ * Test utilities.
+ * TODO: Cleanup (remove unused and obsolete methods).
+ */
+public class TestUtils {
+    /**
+     * Collection of static methods used in math unit tests.
+     */
+    private TestUtils() {
+        super();
+    }
+
+    /**
+     * Verifies that expected and actual are within delta, or are both NaN or
+     * infinities of the same sign.
+     */
+    public static void assertEquals(double expected, double actual, double delta) {
+        Assert.assertEquals(null, expected, actual, delta);
+    }
+
+    /**
+     * Verifies that expected and actual are within delta, or are both NaN or
+     * infinities of the same sign.
+     */
+    public static void assertEquals(String msg, double expected, double actual, double delta) {
+        // check for NaN
+        if(Double.isNaN(expected)){
+            Assert.assertTrue("" + actual + " is not NaN.",
+                Double.isNaN(actual));
+        } else {
+            Assert.assertEquals(msg, expected, actual, delta);
+        }
+    }
+
+    /**
+     * Verifies that the two arguments are exactly the same, either
+     * both NaN or infinities of same sign, or identical floating point values.
+     */
+    public static void assertSame(double expected, double actual) {
+     Assert.assertEquals(expected, actual, 0);
+    }
+
+    /**
+     * Verifies that real and imaginary parts of the two complex arguments
+     * are exactly the same.  Also ensures that NaN / infinite components match.
+     */
+    public static void assertSame(Complex expected, Complex actual) {
+        assertSame(expected.getReal(), actual.getReal());
+        assertSame(expected.getImaginary(), actual.getImaginary());
+    }
+
+    /**
+     * Verifies that real and imaginary parts of the two complex arguments
+     * differ by at most delta.  Also ensures that NaN / infinite components match.
+     */
+    public static void assertEquals(Complex expected, Complex actual, double delta) {
+        Assert.assertEquals(expected.getReal(), actual.getReal(), delta);
+        Assert.assertEquals(expected.getImaginary(), actual.getImaginary(), delta);
+    }
+
+    /**
+     * Verifies that two double arrays have equal entries, up to tolerance
+     */
+    public static void assertEquals(double expected[], double observed[], double tolerance) {
+        assertEquals("Array comparison failure", expected, observed, tolerance);
+    }
+
+    /**
+     * Serializes an object to a bytes array and then recovers the object from the bytes array.
+     * Returns the deserialized object.
+     *
+     * @param o  object to serialize and recover
+     * @return  the recovered, deserialized object
+     */
+    public static Object serializeAndRecover(Object o) {
+        try {
+            // serialize the Object
+            ByteArrayOutputStream bos = new ByteArrayOutputStream();
+            ObjectOutputStream so = new ObjectOutputStream(bos);
+            so.writeObject(o);
+
+            // deserialize the Object
+            ByteArrayInputStream bis = new ByteArrayInputStream(bos.toByteArray());
+            ObjectInputStream si = new ObjectInputStream(bis);
+            return si.readObject();
+        } catch (IOException ioe) {
+            return null;
+        } catch (ClassNotFoundException cnfe) {
+            return null;
+        }
+    }
+
+    /**
+     * Verifies that serialization preserves equals and hashCode.
+     * Serializes the object, then recovers it and checks equals and hash code.
+     *
+     * @param object  the object to serialize and recover
+     */
+    public static void checkSerializedEquality(Object object) {
+        Object object2 = serializeAndRecover(object);
+        Assert.assertEquals("Equals check", object, object2);
+        Assert.assertEquals("HashCode check", object.hashCode(), object2.hashCode());
+    }
+
+    /**
+     * Verifies that the relative error in actual vs. expected is less than or
+     * equal to relativeError.  If expected is infinite or NaN, actual must be
+     * the same (NaN or infinity of the same sign).
+     *
+     * @param expected expected value
+     * @param actual  observed value
+     * @param relativeError  maximum allowable relative error
+     */
+    public static void assertRelativelyEquals(double expected, double actual,
+            double relativeError) {
+        assertRelativelyEquals(null, expected, actual, relativeError);
+    }
+
+    /**
+     * Verifies that the relative error in actual vs. expected is less than or
+     * equal to relativeError.  If expected is infinite or NaN, actual must be
+     * the same (NaN or infinity of the same sign).
+     *
+     * @param msg  message to return with failure
+     * @param expected expected value
+     * @param actual  observed value
+     * @param relativeError  maximum allowable relative error
+     */
+    public static void assertRelativelyEquals(String msg, double expected,
+            double actual, double relativeError) {
+        if (Double.isNaN(expected)) {
+            Assert.assertTrue(msg, Double.isNaN(actual));
+        } else if (Double.isNaN(actual)) {
+            Assert.assertTrue(msg, Double.isNaN(expected));
+        } else if (Double.isInfinite(actual) || Double.isInfinite(expected)) {
+            Assert.assertEquals(expected, actual, relativeError);
+        } else if (expected == 0.0) {
+            Assert.assertEquals(msg, actual, expected, relativeError);
+        } else {
+            double absError = Math.abs(expected) * relativeError;
+            Assert.assertEquals(msg, expected, actual, absError);
+        }
+    }
+
+    /**
+     * Fails iff values does not contain a number within epsilon of z.
+     *
+     * @param msg  message to return with failure
+     * @param values complex array to search
+     * @param z  value sought
+     * @param epsilon  tolerance
+     */
+    public static void assertContains(String msg, Complex[] values,
+                                      Complex z, double epsilon) {
+        for (Complex value : values) {
+            if (Precision.equals(value.getReal(), z.getReal(), epsilon) &&
+                Precision.equals(value.getImaginary(), z.getImaginary(), epsilon)) {
+                return;
+            }
+        }
+        Assert.fail(msg + " Unable to find " + z);
+    }
+
+    /**
+     * Fails iff values does not contain a number within epsilon of z.
+     *
+     * @param values complex array to search
+     * @param z  value sought
+     * @param epsilon  tolerance
+     */
+    public static void assertContains(Complex[] values,
+            Complex z, double epsilon) {
+        assertContains(null, values, z, epsilon);
+    }
+
+    /**
+     * Fails iff values does not contain a number within epsilon of x.
+     *
+     * @param msg  message to return with failure
+     * @param values double array to search
+     * @param x value sought
+     * @param epsilon  tolerance
+     */
+    public static void assertContains(String msg, double[] values,
+            double x, double epsilon) {
+        for (double value : values) {
+            if (Precision.equals(value, x, epsilon)) {
+                return;
+            }
+        }
+        Assert.fail(msg + " Unable to find " + x);
+    }
+
+    /**
+     * Fails iff values does not contain a number within epsilon of x.
+     *
+     * @param values double array to search
+     * @param x value sought
+     * @param epsilon  tolerance
+     */
+    public static void assertContains(double[] values, double x,
+            double epsilon) {
+       assertContains(null, values, x, epsilon);
+    }
+
+    /** verifies that two arrays are close (sup norm) */
+    public static void assertEquals(String msg, double[] expected, double[] observed, double tolerance) {
+        StringBuilder out = new StringBuilder(msg);
+        if (expected.length != observed.length) {
+            out.append("\n Arrays not same length. \n");
+            out.append("expected has length ");
+            out.append(expected.length);
+            out.append(" observed length = ");
+            out.append(observed.length);
+            Assert.fail(out.toString());
+        }
+        boolean failure = false;
+        for (int i=0; i < expected.length; i++) {
+            if (!equalsIncludingNaN(expected[i], observed[i], tolerance)) {
+                failure = true;
+                out.append("\n Elements at index ");
+                out.append(i);
+                out.append(" differ. ");
+                out.append(" expected = ");
+                out.append(expected[i]);
+                out.append(" observed = ");
+                out.append(observed[i]);
+            }
+        }
+        if (failure) {
+            Assert.fail(out.toString());
+        }
+    }
+
+    /** verifies that two arrays are close (sup norm) */
+    public static void assertEquals(String msg, float[] expected, float[] observed, float tolerance) {
+        StringBuilder out = new StringBuilder(msg);
+        if (expected.length != observed.length) {
+            out.append("\n Arrays not same length. \n");
+            out.append("expected has length ");
+            out.append(expected.length);
+            out.append(" observed length = ");
+            out.append(observed.length);
+            Assert.fail(out.toString());
+        }
+        boolean failure = false;
+        for (int i=0; i < expected.length; i++) {
+            if (!equalsIncludingNaN(expected[i], observed[i], tolerance)) {
+                failure = true;
+                out.append("\n Elements at index ");
+                out.append(i);
+                out.append(" differ. ");
+                out.append(" expected = ");
+                out.append(expected[i]);
+                out.append(" observed = ");
+                out.append(observed[i]);
+            }
+        }
+        if (failure) {
+            Assert.fail(out.toString());
+        }
+    }
+
+    /** verifies that two arrays are close (sup norm) */
+    public static void assertEquals(String msg, Complex[] expected, Complex[] observed, double tolerance) {
+        StringBuilder out = new StringBuilder(msg);
+        if (expected.length != observed.length) {
+            out.append("\n Arrays not same length. \n");
+            out.append("expected has length ");
+            out.append(expected.length);
+            out.append(" observed length = ");
+            out.append(observed.length);
+            Assert.fail(out.toString());
+        }
+        boolean failure = false;
+        for (int i=0; i < expected.length; i++) {
+            if (!equalsIncludingNaN(expected[i].getReal(), observed[i].getReal(), tolerance)) {
+                failure = true;
+                out.append("\n Real elements at index ");
+                out.append(i);
+                out.append(" differ. ");
+                out.append(" expected = ");
+                out.append(expected[i].getReal());
+                out.append(" observed = ");
+                out.append(observed[i].getReal());
+            }
+            if (!equalsIncludingNaN(expected[i].getImaginary(), observed[i].getImaginary(), tolerance)) {
+                failure = true;
+                out.append("\n Imaginary elements at index ");
+                out.append(i);
+                out.append(" differ. ");
+                out.append(" expected = ");
+                out.append(expected[i].getImaginary());
+                out.append(" observed = ");
+                out.append(observed[i].getImaginary());
+            }
+        }
+        if (failure) {
+            Assert.fail(out.toString());
+        }
+    }
+
+    /**
+     * Updates observed counts of values in quartiles.
+     * counts[0] <-> 1st quartile ... counts[3] <-> top quartile
+     */
+    public static void updateCounts(double value, long[] counts, double[] quartiles) {
+        if (value < quartiles[0]) {
+            counts[0]++;
+        } else if (value > quartiles[2]) {
+            counts[3]++;
+        } else if (value > quartiles[1]) {
+            counts[2]++;
+        } else {
+            counts[1]++;
+        }
+    }
+
+    /**
+     * Eliminates points with zero mass from densityPoints and densityValues parallel
+     * arrays.  Returns the number of positive mass points and collapses the arrays so
+     * that the first <returned value> elements of the input arrays represent the positive
+     * mass points.
+     */
+    public static int eliminateZeroMassPoints(int[] densityPoints, double[] densityValues) {
+        int positiveMassCount = 0;
+        for (int i = 0; i < densityValues.length; i++) {
+            if (densityValues[i] > 0) {
+                positiveMassCount++;
+            }
+        }
+        if (positiveMassCount < densityValues.length) {
+            int[] newPoints = new int[positiveMassCount];
+            double[] newValues = new double[positiveMassCount];
+            int j = 0;
+            for (int i = 0; i < densityValues.length; i++) {
+                if (densityValues[i] > 0) {
+                    newPoints[j] = densityPoints[i];
+                    newValues[j] = densityValues[i];
+                    j++;
+                }
+            }
+            System.arraycopy(newPoints,0,densityPoints,0,positiveMassCount);
+            System.arraycopy(newValues,0,densityValues,0,positiveMassCount);
+        }
+        return positiveMassCount;
+    }
+
+    /**
+     * Returns true if the arguments are both NaN, are equal or are within the range
+     * of allowed error (inclusive).
+     *
+     * @param x first value
+     * @param y second value
+     * @param eps the amount of absolute error to allow.
+     * @return {@code true} if the values are equal or within range of each other,
+     * or both are NaN.
+     * @since 2.2
+     */
+    private static boolean equalsIncludingNaN(double x, double y, double eps) {
+        return equalsIncludingNaN(x, y) || (Math.abs(y - x) <= eps);
+    }
+
+    /**
+     * Returns true if the arguments are both NaN or they are
+     * equal as defined by {@link #equals(double,double) equals(x, y, 1)}.
+     *
+     * @param x first value
+     * @param y second value
+     * @return {@code true} if the values are equal or both are NaN.
+     * @since 2.2
+     */
+    private static boolean equalsIncludingNaN(double x, double y) {
+        return (x != x || y != y) ? !(x != x ^ y != y) : Precision.equals(x, y, 1);
+    }
+
+
+}
+
+

http://git-wip-us.apache.org/repos/asf/commons-numbers/blob/c4541327/commons-numbers-core/LICENSE.txt
----------------------------------------------------------------------
diff --git a/commons-numbers-core/LICENSE.txt b/commons-numbers-core/LICENSE.txt
new file mode 100644
index 0000000..261eeb9
--- /dev/null
+++ b/commons-numbers-core/LICENSE.txt
@@ -0,0 +1,201 @@
+                                 Apache License
+                           Version 2.0, January 2004
+                        http://www.apache.org/licenses/
+
+   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+
+   1. Definitions.
+
+      "License" shall mean the terms and conditions for use, reproduction,
+      and distribution as defined by Sections 1 through 9 of this document.
+
+      "Licensor" shall mean the copyright owner or entity authorized by
+      the copyright owner that is granting the License.
+
+      "Legal Entity" shall mean the union of the acting entity and all
+      other entities that control, are controlled by, or are under common
+      control with that entity. For the purposes of this definition,
+      "control" means (i) the power, direct or indirect, to cause the
+      direction or management of such entity, whether by contract or
+      otherwise, or (ii) ownership of fifty percent (50%) or more of the
+      outstanding shares, or (iii) beneficial ownership of such entity.
+
+      "You" (or "Your") shall mean an individual or Legal Entity
+      exercising permissions granted by this License.
+
+      "Source" form shall mean the preferred form for making modifications,
+      including but not limited to software source code, documentation
+      source, and configuration files.
+
+      "Object" form shall mean any form resulting from mechanical
+      transformation or translation of a Source form, including but
+      not limited to compiled object code, generated documentation,
+      and conversions to other media types.
+
+      "Work" shall mean the work of authorship, whether in Source or
+      Object form, made available under the License, as indicated by a
+      copyright notice that is included in or attached to the work
+      (an example is provided in the Appendix below).
+
+      "Derivative Works" shall mean any work, whether in Source or Object
+      form, that is based on (or derived from) the Work and for which the
+      editorial revisions, annotations, elaborations, or other modifications
+      represent, as a whole, an original work of authorship. For the purposes
+      of this License, Derivative Works shall not include works that remain
+      separable from, or merely link (or bind by name) to the interfaces of,
+      the Work and Derivative Works thereof.
+
+      "Contribution" shall mean any work of authorship, including
+      the original version of the Work and any modifications or additions
+      to that Work or Derivative Works thereof, that is intentionally
+      submitted to Licensor for inclusion in the Work by the copyright owner
+      or by an individual or Legal Entity authorized to submit on behalf of
+      the copyright owner. For the purposes of this definition, "submitted"
+      means any form of electronic, verbal, or written communication sent
+      to the Licensor or its representatives, including but not limited to
+      communication on electronic mailing lists, source code control systems,
+      and issue tracking systems that are managed by, or on behalf of, the
+      Licensor for the purpose of discussing and improving the Work, but
+      excluding communication that is conspicuously marked or otherwise
+      designated in writing by the copyright owner as "Not a Contribution."
+
+      "Contributor" shall mean Licensor and any individual or Legal Entity
+      on behalf of whom a Contribution has been received by Licensor and
+      subsequently incorporated within the Work.
+
+   2. Grant of Copyright License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      copyright license to reproduce, prepare Derivative Works of,
+      publicly display, publicly perform, sublicense, and distribute the
+      Work and such Derivative Works in Source or Object form.
+
+   3. Grant of Patent License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      (except as stated in this section) patent license to make, have made,
+      use, offer to sell, sell, import, and otherwise transfer the Work,
+      where such license applies only to those patent claims licensable
+      by such Contributor that are necessarily infringed by their
+      Contribution(s) alone or by combination of their Contribution(s)
+      with the Work to which such Contribution(s) was submitted. If You
+      institute patent litigation against any entity (including a
+      cross-claim or counterclaim in a lawsuit) alleging that the Work
+      or a Contribution incorporated within the Work constitutes direct
+      or contributory patent infringement, then any patent licenses
+      granted to You under this License for that Work shall terminate
+      as of the date such litigation is filed.
+
+   4. Redistribution. You may reproduce and distribute copies of the
+      Work or Derivative Works thereof in any medium, with or without
+      modifications, and in Source or Object form, provided that You
+      meet the following conditions:
+
+      (a) You must give any other recipients of the Work or
+          Derivative Works a copy of this License; and
+
+      (b) You must cause any modified files to carry prominent notices
+          stating that You changed the files; and
+
+      (c) You must retain, in the Source form of any Derivative Works
+          that You distribute, all copyright, patent, trademark, and
+          attribution notices from the Source form of the Work,
+          excluding those notices that do not pertain to any part of
+          the Derivative Works; and
+
+      (d) If the Work includes a "NOTICE" text file as part of its
+          distribution, then any Derivative Works that You distribute must
+          include a readable copy of the attribution notices contained
+          within such NOTICE file, excluding those notices that do not
+          pertain to any part of the Derivative Works, in at least one
+          of the following places: within a NOTICE text file distributed
+          as part of the Derivative Works; within the Source form or
+          documentation, if provided along with the Derivative Works; or,
+          within a display generated by the Derivative Works, if and
+          wherever such third-party notices normally appear. The contents
+          of the NOTICE file are for informational purposes only and
+          do not modify the License. You may add Your own attribution
+          notices within Derivative Works that You distribute, alongside
+          or as an addendum to the NOTICE text from the Work, provided
+          that such additional attribution notices cannot be construed
+          as modifying the License.
+
+      You may add Your own copyright statement to Your modifications and
+      may provide additional or different license terms and conditions
+      for use, reproduction, or distribution of Your modifications, or
+      for any such Derivative Works as a whole, provided Your use,
+      reproduction, and distribution of the Work otherwise complies with
+      the conditions stated in this License.
+
+   5. Submission of Contributions. Unless You explicitly state otherwise,
+      any Contribution intentionally submitted for inclusion in the Work
+      by You to the Licensor shall be under the terms and conditions of
+      this License, without any additional terms or conditions.
+      Notwithstanding the above, nothing herein shall supersede or modify
+      the terms of any separate license agreement you may have executed
+      with Licensor regarding such Contributions.
+
+   6. Trademarks. This License does not grant permission to use the trade
+      names, trademarks, service marks, or product names of the Licensor,
+      except as required for reasonable and customary use in describing the
+      origin of the Work and reproducing the content of the NOTICE file.
+
+   7. Disclaimer of Warranty. Unless required by applicable law or
+      agreed to in writing, Licensor provides the Work (and each
+      Contributor provides its Contributions) on an "AS IS" BASIS,
+      WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+      implied, including, without limitation, any warranties or conditions
+      of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A
+      PARTICULAR PURPOSE. You are solely responsible for determining the
+      appropriateness of using or redistributing the Work and assume any
+      risks associated with Your exercise of permissions under this License.
+
+   8. Limitation of Liability. In no event and under no legal theory,
+      whether in tort (including negligence), contract, or otherwise,
+      unless required by applicable law (such as deliberate and grossly
+      negligent acts) or agreed to in writing, shall any Contributor be
+      liable to You for damages, including any direct, indirect, special,
+      incidental, or consequential damages of any character arising as a
+      result of this License or out of the use or inability to use the
+      Work (including but not limited to damages for loss of goodwill,
+      work stoppage, computer failure or malfunction, or any and all
+      other commercial damages or losses), even if such Contributor
+      has been advised of the possibility of such damages.
+
+   9. Accepting Warranty or Additional Liability. While redistributing
+      the Work or Derivative Works thereof, You may choose to offer,
+      and charge a fee for, acceptance of support, warranty, indemnity,
+      or other liability obligations and/or rights consistent with this
+      License. However, in accepting such obligations, You may act only
+      on Your own behalf and on Your sole responsibility, not on behalf
+      of any other Contributor, and only if You agree to indemnify,
+      defend, and hold each Contributor harmless for any liability
+      incurred by, or claims asserted against, such Contributor by reason
+      of your accepting any such warranty or additional liability.
+
+   END OF TERMS AND CONDITIONS
+
+   APPENDIX: How to apply the Apache License to your work.
+
+      To apply the Apache License to your work, attach the following
+      boilerplate notice, with the fields enclosed by brackets "[]"
+      replaced with your own identifying information. (Don't include
+      the brackets!)  The text should be enclosed in the appropriate
+      comment syntax for the file format. We also recommend that a
+      file or class name and description of purpose be included on the
+      same "printed page" as the copyright notice for easier
+      identification within third-party archives.
+
+   Copyright [yyyy] [name of copyright owner]
+
+   Licensed 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.

http://git-wip-us.apache.org/repos/asf/commons-numbers/blob/c4541327/commons-numbers-core/NOTICE.txt
----------------------------------------------------------------------
diff --git a/commons-numbers-core/NOTICE.txt b/commons-numbers-core/NOTICE.txt
new file mode 100644
index 0000000..ea6ae07
--- /dev/null
+++ b/commons-numbers-core/NOTICE.txt
@@ -0,0 +1,6 @@
+Apache Commons Numbers
+Copyright 2001-2016 The Apache Software Foundation
+
+This product includes software developed at
+The Apache Software Foundation (http://www.apache.org/).
+

http://git-wip-us.apache.org/repos/asf/commons-numbers/blob/c4541327/commons-numbers-core/README.md
----------------------------------------------------------------------
diff --git a/commons-numbers-core/README.md b/commons-numbers-core/README.md
new file mode 100644
index 0000000..0701bed
--- /dev/null
+++ b/commons-numbers-core/README.md
@@ -0,0 +1,98 @@
+<!---
+ 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.
+-->
+<!---
+ +======================================================================+
+ |****                                                              ****|
+ |****      THIS FILE IS GENERATED BY THE COMMONS BUILD PLUGIN      ****|
+ |****                    DO NOT EDIT DIRECTLY                      ****|
+ |****                                                              ****|
+ +======================================================================+
+ | TEMPLATE FILE: readme-md-template.md                                 |
+ | commons-build-plugin/trunk/src/main/resources/commons-xdoc-templates |
+ +======================================================================+
+ |                                                                      |
+ | 1) Re-generate using: mvn commons:readme-md                          |
+ |                                                                      |
+ | 2) Set the following properties in the component's pom:              |
+ |    - commons.componentid (required, alphabetic, lower case)          |
+ |    - commons.release.version (required)                              |
+ |                                                                      |
+ | 3) Example Properties                                                |
+ |                                                                      |
+ |  <properties>                                                        |
+ |    <commons.componentid>math</commons.componentid>                   |
+ |    <commons.release.version>1.2</commons.release.version>            |
+ |  </properties>                                                       |
+ |                                                                      |
+ +======================================================================+
+--->
+Apache Commons Numbers Core
+===================
+
+Basic utilities.
+
+Documentation
+-------------
+
+More information can be found on the [homepage](https://commons.apache.org/proper/commons-numbers).
+The [JavaDoc](https://commons.apache.org/proper/commons-numbers/javadocs/api-release) can be browsed.
+Questions related to the usage of Apache Commons Numbers Core should be posted to the [user mailing list][ml].
+
+Where can I get the latest release?
+-----------------------------------
+You can download source and binaries from our [download page](https://commons.apache.org/proper/commons-numbers/download_numbers.cgi).
+
+Alternatively you can pull it from the central Maven repositories:
+
+```xml
+<dependency>
+  <groupId>org.apache.commons</groupId>
+  <artifactId>commons-numbers-core</artifactId>
+  <version>1.0</version>
+</dependency>
+```
+
+Contributing
+------------
+
+We accept PRs via github. The [developer mailing list][ml] is the main channel of communication for contributors.
+There are some guidelines which will make applying PRs easier for us:
++ No tabs! Please use spaces for indentation.
++ Respect the code style.
++ Create minimal diffs - disable on save actions like reformat source code or organize imports. If you feel the source code should be reformatted create a separate PR for this change.
++ Provide JUnit tests for your changes and make sure your changes don't break any existing tests by running ```mvn clean test```.
+
+If you plan to contribute on a regular basis, please consider filing a [contributor license agreement](https://www.apache.org/licenses/#clas).
+You can learn more about contributing via GitHub in our [contribution guidelines](CONTRIBUTING.md).
+
+License
+-------
+Code is under the [Apache Licence v2](https://www.apache.org/licenses/LICENSE-2.0.txt).
+
+Donations
+---------
+You like Apache Commons Numbers Core? Then [donate back to the ASF](https://www.apache.org/foundation/contributing.html) to support the development.
+
+Additional Resources
+--------------------
+
++ [Apache Commons Homepage](https://commons.apache.org/)
++ [Apache Bugtracker (JIRA)](https://issues.apache.org/jira/)
++ [Apache Commons Twitter Account](https://twitter.com/ApacheCommons)
++ #apachecommons IRC channel on freenode.org
+
+[ml]:https://commons.apache.org/mail-lists.html

http://git-wip-us.apache.org/repos/asf/commons-numbers/blob/c4541327/commons-numbers-core/pom.xml
----------------------------------------------------------------------
diff --git a/commons-numbers-core/pom.xml b/commons-numbers-core/pom.xml
new file mode 100644
index 0000000..39dbdcb
--- /dev/null
+++ b/commons-numbers-core/pom.xml
@@ -0,0 +1,46 @@
+<?xml version="1.0"?>
+<!--
+   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.
+-->
+<project xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"
+         xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
+  <modelVersion>4.0.0</modelVersion>
+
+  <parent>
+    <groupId>org.apache.commons</groupId>
+    <artifactId>commons-numbers-parent</artifactId>
+    <version>1.0-SNAPSHOT</version>
+  </parent>
+
+  <groupId>org.apache.commons</groupId>
+  <artifactId>commons-numbers-core</artifactId>
+  <version>1.0-SNAPSHOT</version>
+  <name>Apache Commons Numbers Core</name>
+
+  <description>Basic utilities.</description>
+
+  <properties>
+    <!-- This value must reflect the current name of the base package. -->
+    <commons.osgi.symbolicName>org.apache.commons.numbers.core</commons.osgi.symbolicName>
+    <!-- OSGi -->
+    <commons.osgi.export>org.apache.commons.numbers.core</commons.osgi.export>
+    <!-- Workaround to avoid duplicating config files. -->
+    <numbers.parent.dir>${basedir}/..</numbers.parent.dir>
+  </properties>
+
+
+</project>

http://git-wip-us.apache.org/repos/asf/commons-numbers/blob/c4541327/commons-numbers-core/src/main/java/org/apache/commons/numbers/core/Precision.java
----------------------------------------------------------------------
diff --git a/commons-numbers-core/src/main/java/org/apache/commons/numbers/core/Precision.java b/commons-numbers-core/src/main/java/org/apache/commons/numbers/core/Precision.java
new file mode 100644
index 0000000..e71e1e4
--- /dev/null
+++ b/commons-numbers-core/src/main/java/org/apache/commons/numbers/core/Precision.java
@@ -0,0 +1,598 @@
+/*
+ * 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.numbers.core;
+
+import java.math.BigDecimal;
+
+/**
+ * Utilities for comparing numbers.
+ */
+public class Precision {
+    /**
+     * <p>
+     * Largest double-precision floating-point number such that
+     * {@code 1 + EPSILON} is numerically equal to 1. This value is an upper
+     * bound on the relative error due to rounding real numbers to double
+     * precision floating-point numbers.
+     * </p>
+     * <p>
+     * In IEEE 754 arithmetic, this is 2<sup>-53</sup>.
+     * </p>
+     *
+     * @see <a href="http://en.wikipedia.org/wiki/Machine_epsilon">Machine epsilon</a>
+     */
+    public static final double EPSILON;
+
+    /**
+     * Safe minimum, such that {@code 1 / SAFE_MIN} does not overflow.
+     * In IEEE 754 arithmetic, this is also the smallest normalized
+     * number 2<sup>-1022</sup>.
+     */
+    public static final double SAFE_MIN;
+
+    /** Exponent offset in IEEE754 representation. */
+    private static final long EXPONENT_OFFSET = 1023l;
+
+    /** Offset to order signed double numbers lexicographically. */
+    private static final long SGN_MASK = 0x8000000000000000L;
+    /** Offset to order signed double numbers lexicographically. */
+    private static final int SGN_MASK_FLOAT = 0x80000000;
+    /** Positive zero. */
+    private static final double POSITIVE_ZERO = 0d;
+    /** Positive zero bits. */
+    private static final long POSITIVE_ZERO_DOUBLE_BITS = Double.doubleToRawLongBits(+0.0);
+    /** Negative zero bits. */
+    private static final long NEGATIVE_ZERO_DOUBLE_BITS = Double.doubleToRawLongBits(-0.0);
+    /** Positive zero bits. */
+    private static final int POSITIVE_ZERO_FLOAT_BITS = Float.floatToRawIntBits(+0.0f);
+    /** Negative zero bits. */
+    private static final int NEGATIVE_ZERO_FLOAT_BITS = Float.floatToRawIntBits(-0.0f);
+
+    static {
+        /*
+         *  This was previously expressed as = 0x1.0p-53;
+         *  However, OpenJDK (Sparc Solaris) cannot handle such small
+         *  constants: MATH-721
+         */
+        EPSILON = Double.longBitsToDouble((EXPONENT_OFFSET - 53l) << 52);
+
+        /*
+         * This was previously expressed as = 0x1.0p-1022;
+         * However, OpenJDK (Sparc Solaris) cannot handle such small
+         * constants: MATH-721
+         */
+        SAFE_MIN = Double.longBitsToDouble((EXPONENT_OFFSET - 1022l) << 52);
+    }
+
+    /**
+     * Private constructor.
+     */
+    private Precision() {}
+
+    /**
+     * Compares two numbers given some amount of allowed error.
+     * The returned value is
+     * <ul>
+     *  <li>
+     *   0 if  {@link #equals(double,double,double) equals(x, y, eps)},
+     *  </li>
+     *  <li>
+     *   negative if !{@link #equals(double,double,double) equals(x, y, eps)} and {@code x < y},
+     *  </li>
+     *  <li>
+     *   positive if !{@link #equals(double,double,double) equals(x, y, eps)} and {@code x > y} or
+     *   either argument is {@code NaN}.
+     *  </li>
+     * </ul>
+     *
+     * @param x First value.
+     * @param y Second value.
+     * @param eps Allowed error when checking for equality.
+     * @return 0 if the value are considered equal, -1 if the first is smaller than
+     * the second, 1 is the first is larger than the second.
+     */
+    public static int compareTo(double x, double y, double eps) {
+        if (equals(x, y, eps)) {
+            return 0;
+        } else if (x < y) {
+            return -1;
+        }
+        return 1;
+    }
+
+    /**
+     * Compares two numbers given some amount of allowed error.
+     * Two float numbers are considered equal if there are {@code (maxUlps - 1)}
+     * (or fewer) floating point numbers between them, i.e. two adjacent floating
+     * point numbers are considered equal.
+     * Adapted from
+     * <a href="http://randomascii.wordpress.com/2012/02/25/comparing-floating-point-numbers-2012-edition/">
+     * Bruce Dawson</a>. Returns {@code false} if either of the arguments is NaN.
+     * The returned value is
+     * <ul>
+     *  <li>
+     *   zero if {@link #equals(double,double,int) equals(x, y, maxUlps)},
+     *  </li>
+     *  <li>
+     *   negative if !{@link #equals(double,double,int) equals(x, y, maxUlps)} and {@code x < y},
+     *  </li>
+     *  <li>
+     *   positive if !{@link #equals(double,double,int) equals(x, y, maxUlps)} and {@code x > y}
+     *       or either argument is {@code NaN}.
+     *  </li>
+     * </ul>
+     *
+     * @param x First value.
+     * @param y Second value.
+     * @param maxUlps {@code (maxUlps - 1)} is the number of floating point
+     * values between {@code x} and {@code y}.
+     * @return 0 if the value are considered equal, -1 if the first is smaller than
+     * the second, 1 is the first is larger than the second.
+     */
+    public static int compareTo(final double x, final double y, final int maxUlps) {
+        if (equals(x, y, maxUlps)) {
+            return 0;
+        } else if (x < y) {
+            return -1;
+        }
+        return 1;
+    }
+
+    /**
+     * Returns true iff they are equal as defined by
+     * {@link #equals(float,float,int) equals(x, y, 1)}.
+     *
+     * @param x first value
+     * @param y second value
+     * @return {@code true} if the values are equal.
+     */
+    public static boolean equals(float x, float y) {
+        return equals(x, y, 1);
+    }
+
+    /**
+     * Returns true if both arguments are NaN or they are
+     * equal as defined by {@link #equals(float,float) equals(x, y, 1)}.
+     *
+     * @param x first value
+     * @param y second value
+     * @return {@code true} if the values are equal or both are NaN.
+     */
+    public static boolean equalsIncludingNaN(float x, float y) {
+        return (x != x || y != y) ? !(x != x ^ y != y) : equals(x, y, 1);
+    }
+
+    /**
+     * Returns true if the arguments are equal or within the range of allowed
+     * error (inclusive).  Returns {@code false} if either of the arguments
+     * is NaN.
+     *
+     * @param x first value
+     * @param y second value
+     * @param eps the amount of absolute error to allow.
+     * @return {@code true} if the values are equal or within range of each other.
+     */
+    public static boolean equals(float x, float y, float eps) {
+        return equals(x, y, 1) || Math.abs(y - x) <= eps;
+    }
+
+    /**
+     * Returns true if the arguments are both NaN, are equal, or are within the range
+     * of allowed error (inclusive).
+     *
+     * @param x first value
+     * @param y second value
+     * @param eps the amount of absolute error to allow.
+     * @return {@code true} if the values are equal or within range of each other,
+     * or both are NaN.
+     */
+    public static boolean equalsIncludingNaN(float x, float y, float eps) {
+        return equalsIncludingNaN(x, y) || (Math.abs(y - x) <= eps);
+    }
+
+    /**
+     * Returns true if the arguments are equal or within the range of allowed
+     * error (inclusive).
+     * Two float numbers are considered equal if there are {@code (maxUlps - 1)}
+     * (or fewer) floating point numbers between them, i.e. two adjacent floating
+     * point numbers are considered equal.
+     * Adapted from <a
+     * href="http://randomascii.wordpress.com/2012/02/25/comparing-floating-point-numbers-2012-edition/">
+     * Bruce Dawson</a>.  Returns {@code false} if either of the arguments is NaN.
+     *
+     * @param x first value
+     * @param y second value
+     * @param maxUlps {@code (maxUlps - 1)} is the number of floating point
+     * values between {@code x} and {@code y}.
+     * @return {@code true} if there are fewer than {@code maxUlps} floating
+     * point values between {@code x} and {@code y}.
+     */
+    public static boolean equals(final float x, final float y, final int maxUlps) {
+
+        final int xInt = Float.floatToRawIntBits(x);
+        final int yInt = Float.floatToRawIntBits(y);
+
+        final boolean isEqual;
+        if (((xInt ^ yInt) & SGN_MASK_FLOAT) == 0) {
+            // number have same sign, there is no risk of overflow
+            isEqual = Math.abs(xInt - yInt) <= maxUlps;
+        } else {
+            // number have opposite signs, take care of overflow
+            final int deltaPlus;
+            final int deltaMinus;
+            if (xInt < yInt) {
+                deltaPlus  = yInt - POSITIVE_ZERO_FLOAT_BITS;
+                deltaMinus = xInt - NEGATIVE_ZERO_FLOAT_BITS;
+            } else {
+                deltaPlus  = xInt - POSITIVE_ZERO_FLOAT_BITS;
+                deltaMinus = yInt - NEGATIVE_ZERO_FLOAT_BITS;
+            }
+
+            if (deltaPlus > maxUlps) {
+                isEqual = false;
+            } else {
+                isEqual = deltaMinus <= (maxUlps - deltaPlus);
+            }
+
+        }
+
+        return isEqual && !Float.isNaN(x) && !Float.isNaN(y);
+
+    }
+
+    /**
+     * Returns true if the arguments are both NaN or if they are equal as defined
+     * by {@link #equals(float,float,int) equals(x, y, maxUlps)}.
+     *
+     * @param x first value
+     * @param y second value
+     * @param maxUlps {@code (maxUlps - 1)} is the number of floating point
+     * values between {@code x} and {@code y}.
+     * @return {@code true} if both arguments are NaN or if there are less than
+     * {@code maxUlps} floating point values between {@code x} and {@code y}.
+     */
+    public static boolean equalsIncludingNaN(float x, float y, int maxUlps) {
+        return (x != x || y != y) ? !(x != x ^ y != y) : equals(x, y, maxUlps);
+    }
+
+    /**
+     * Returns true iff they are equal as defined by
+     * {@link #equals(double,double,int) equals(x, y, 1)}.
+     *
+     * @param x first value
+     * @param y second value
+     * @return {@code true} if the values are equal.
+     */
+    public static boolean equals(double x, double y) {
+        return equals(x, y, 1);
+    }
+
+    /**
+     * Returns true if the arguments are both NaN or they are
+     * equal as defined by {@link #equals(double,double) equals(x, y, 1)}.
+     *
+     * @param x first value
+     * @param y second value
+     * @return {@code true} if the values are equal or both are NaN.
+     */
+    public static boolean equalsIncludingNaN(double x, double y) {
+        return (x != x || y != y) ? !(x != x ^ y != y) : equals(x, y, 1);
+    }
+
+    /**
+     * Returns {@code true} if there is no double value strictly between the
+     * arguments or the difference between them is within the range of allowed
+     * error (inclusive). Returns {@code false} if either of the arguments
+     * is NaN.
+     *
+     * @param x First value.
+     * @param y Second value.
+     * @param eps Amount of allowed absolute error.
+     * @return {@code true} if the values are two adjacent floating point
+     * numbers or they are within range of each other.
+     */
+    public static boolean equals(double x, double y, double eps) {
+        return equals(x, y, 1) || Math.abs(y - x) <= eps;
+    }
+
+    /**
+     * Returns {@code true} if there is no double value strictly between the
+     * arguments or the relative difference between them is less than or equal
+     * to the given tolerance. Returns {@code false} if either of the arguments
+     * is NaN.
+     *
+     * @param x First value.
+     * @param y Second value.
+     * @param eps Amount of allowed relative error.
+     * @return {@code true} if the values are two adjacent floating point
+     * numbers or they are within range of each other.
+     */
+    public static boolean equalsWithRelativeTolerance(double x, double y, double eps) {
+        if (equals(x, y, 1)) {
+            return true;
+        }
+
+        final double absoluteMax = Math.max(Math.abs(x), Math.abs(y));
+        final double relativeDifference = Math.abs((x - y) / absoluteMax);
+
+        return relativeDifference <= eps;
+    }
+
+    /**
+     * Returns true if the arguments are both NaN, are equal or are within the range
+     * of allowed error (inclusive).
+     *
+     * @param x first value
+     * @param y second value
+     * @param eps the amount of absolute error to allow.
+     * @return {@code true} if the values are equal or within range of each other,
+     * or both are NaN.
+     */
+    public static boolean equalsIncludingNaN(double x, double y, double eps) {
+        return equalsIncludingNaN(x, y) || (Math.abs(y - x) <= eps);
+    }
+
+    /**
+     * Returns true if the arguments are equal or within the range of allowed
+     * error (inclusive).
+     * <p>
+     * Two float numbers are considered equal if there are {@code (maxUlps - 1)}
+     * (or fewer) floating point numbers between them, i.e. two adjacent
+     * floating point numbers are considered equal.
+     * </p>
+     * <p>
+     * Adapted from <a
+     * href="http://randomascii.wordpress.com/2012/02/25/comparing-floating-point-numbers-2012-edition/">
+     * Bruce Dawson</a>. Returns {@code false} if either of the arguments is NaN.
+     * </p>
+     *
+     * @param x first value
+     * @param y second value
+     * @param maxUlps {@code (maxUlps - 1)} is the number of floating point
+     * values between {@code x} and {@code y}.
+     * @return {@code true} if there are fewer than {@code maxUlps} floating
+     * point values between {@code x} and {@code y}.
+     */
+    public static boolean equals(final double x, final double y, final int maxUlps) {
+
+        final long xInt = Double.doubleToRawLongBits(x);
+        final long yInt = Double.doubleToRawLongBits(y);
+
+        final boolean isEqual;
+        if (((xInt ^ yInt) & SGN_MASK) == 0l) {
+            // number have same sign, there is no risk of overflow
+            isEqual = Math.abs(xInt - yInt) <= maxUlps;
+        } else {
+            // number have opposite signs, take care of overflow
+            final long deltaPlus;
+            final long deltaMinus;
+            if (xInt < yInt) {
+                deltaPlus  = yInt - POSITIVE_ZERO_DOUBLE_BITS;
+                deltaMinus = xInt - NEGATIVE_ZERO_DOUBLE_BITS;
+            } else {
+                deltaPlus  = xInt - POSITIVE_ZERO_DOUBLE_BITS;
+                deltaMinus = yInt - NEGATIVE_ZERO_DOUBLE_BITS;
+            }
+
+            if (deltaPlus > maxUlps) {
+                isEqual = false;
+            } else {
+                isEqual = deltaMinus <= (maxUlps - deltaPlus);
+            }
+
+        }
+
+        return isEqual && !Double.isNaN(x) && !Double.isNaN(y);
+
+    }
+
+    /**
+     * Returns true if both arguments are NaN or if they are equal as defined
+     * by {@link #equals(double,double,int) equals(x, y, maxUlps)}.
+     *
+     * @param x first value
+     * @param y second value
+     * @param maxUlps {@code (maxUlps - 1)} is the number of floating point
+     * values between {@code x} and {@code y}.
+     * @return {@code true} if both arguments are NaN or if there are less than
+     * {@code maxUlps} floating point values between {@code x} and {@code y}.
+     */
+    public static boolean equalsIncludingNaN(double x, double y, int maxUlps) {
+        return (x != x || y != y) ? !(x != x ^ y != y) : equals(x, y, maxUlps);
+    }
+
+    /**
+     * Rounds the given value to the specified number of decimal places.
+     * The value is rounded using the {@link BigDecimal#ROUND_HALF_UP} method.
+     *
+     * @param x Value to round.
+     * @param scale Number of digits to the right of the decimal point.
+     * @return the rounded value.
+     */
+    public static double round(double x, int scale) {
+        return round(x, scale, BigDecimal.ROUND_HALF_UP);
+    }
+
+    /**
+     * Rounds the given value to the specified number of decimal places.
+     * The value is rounded using the given method which is any method defined
+     * in {@link BigDecimal}.
+     * If {@code x} is infinite or {@code NaN}, then the value of {@code x} is
+     * returned unchanged, regardless of the other parameters.
+     *
+     * @param x Value to round.
+     * @param scale Number of digits to the right of the decimal point.
+     * @param roundingMethod Rounding method as defined in {@link BigDecimal}.
+     * @return the rounded value.
+     * @throws ArithmeticException if {@code roundingMethod == ROUND_UNNECESSARY}
+     * and the specified scaling operation would require rounding.
+     * @throws IllegalArgumentException if {@code roundingMethod} does not
+     * represent a valid rounding mode.
+     */
+    public static double round(double x, int scale, int roundingMethod) {
+        try {
+            final double rounded = (new BigDecimal(Double.toString(x))
+                   .setScale(scale, roundingMethod))
+                   .doubleValue();
+            // MATH-1089: negative values rounded to zero should result in negative zero
+            return rounded == POSITIVE_ZERO ? POSITIVE_ZERO * x : rounded;
+        } catch (NumberFormatException ex) {
+            if (Double.isInfinite(x)) {
+                return x;
+            } else {
+                return Double.NaN;
+            }
+        }
+    }
+
+    /**
+     * Rounds the given value to the specified number of decimal places.
+     * The value is rounded using the {@link BigDecimal#ROUND_HALF_UP} method.
+     *
+     * @param x Value to round.
+     * @param scale Number of digits to the right of the decimal point.
+     * @return the rounded value.
+     */
+    public static float round(float x, int scale) {
+        return round(x, scale, BigDecimal.ROUND_HALF_UP);
+    }
+
+    /**
+     * Rounds the given value to the specified number of decimal places.
+     * The value is rounded using the given method which is any method defined
+     * in {@link BigDecimal}.
+     *
+     * @param x Value to round.
+     * @param scale Number of digits to the right of the decimal point.
+     * @param roundingMethod Rounding method as defined in {@link BigDecimal}.
+     * @return the rounded value.
+     * @throws ArithmeticException if an exact operation is required but result is not exact
+     * @throws IllegalArgumentException if {@code roundingMethod} is not a valid rounding method.
+     */
+    public static float round(float x, int scale, int roundingMethod) {
+        final float sign = Math.copySign(1f, x);
+        final float factor = (float) Math.pow(10.0f, scale) * sign;
+        return (float) roundUnscaled(x * factor, sign, roundingMethod) / factor;
+    }
+
+    /**
+     * Rounds the given non-negative value to the "nearest" integer. Nearest is
+     * determined by the rounding method specified. Rounding methods are defined
+     * in {@link BigDecimal}.
+     *
+     * @param unscaled Value to round.
+     * @param sign Sign of the original, scaled value.
+     * @param roundingMethod Rounding method, as defined in {@link BigDecimal}.
+     * @return the rounded value.
+     * @throws ArithmeticException if an exact operation is required but result is not exact
+     * @throws IllegalArgumentException if {@code roundingMethod} is not a valid rounding method.
+     */
+    private static double roundUnscaled(double unscaled,
+                                        double sign,
+                                        int roundingMethod) {
+        switch (roundingMethod) {
+        case BigDecimal.ROUND_CEILING :
+            if (sign == -1) {
+                unscaled = Math.floor(Math.nextAfter(unscaled, Double.NEGATIVE_INFINITY));
+            } else {
+                unscaled = Math.ceil(Math.nextAfter(unscaled, Double.POSITIVE_INFINITY));
+            }
+            break;
+        case BigDecimal.ROUND_DOWN :
+            unscaled = Math.floor(Math.nextAfter(unscaled, Double.NEGATIVE_INFINITY));
+            break;
+        case BigDecimal.ROUND_FLOOR :
+            if (sign == -1) {
+                unscaled = Math.ceil(Math.nextAfter(unscaled, Double.POSITIVE_INFINITY));
+            } else {
+                unscaled = Math.floor(Math.nextAfter(unscaled, Double.NEGATIVE_INFINITY));
+            }
+            break;
+        case BigDecimal.ROUND_HALF_DOWN : {
+            unscaled = Math.nextAfter(unscaled, Double.NEGATIVE_INFINITY);
+            double fraction = unscaled - Math.floor(unscaled);
+            if (fraction > 0.5) {
+                unscaled = Math.ceil(unscaled);
+            } else {
+                unscaled = Math.floor(unscaled);
+            }
+            break;
+        }
+        case BigDecimal.ROUND_HALF_EVEN : {
+            double fraction = unscaled - Math.floor(unscaled);
+            if (fraction > 0.5) {
+                unscaled = Math.ceil(unscaled);
+            } else if (fraction < 0.5) {
+                unscaled = Math.floor(unscaled);
+            } else {
+                // The following equality test is intentional and needed for rounding purposes
+                if (Math.floor(unscaled) / 2.0 == Math.floor(Math.floor(unscaled) / 2.0)) { // even
+                    unscaled = Math.floor(unscaled);
+                } else { // odd
+                    unscaled = Math.ceil(unscaled);
+                }
+            }
+            break;
+        }
+        case BigDecimal.ROUND_HALF_UP : {
+            unscaled = Math.nextAfter(unscaled, Double.POSITIVE_INFINITY);
+            double fraction = unscaled - Math.floor(unscaled);
+            if (fraction >= 0.5) {
+                unscaled = Math.ceil(unscaled);
+            } else {
+                unscaled = Math.floor(unscaled);
+            }
+            break;
+        }
+        case BigDecimal.ROUND_UNNECESSARY :
+            if (unscaled != Math.floor(unscaled)) {
+                throw new ArithmeticException();
+            }
+            break;
+        case BigDecimal.ROUND_UP :
+            // do not round if the discarded fraction is equal to zero
+            if (unscaled != Math.floor(unscaled)) {
+                unscaled = Math.ceil(Math.nextAfter(unscaled, Double.POSITIVE_INFINITY));
+            }
+            break;
+        default :
+            throw new IllegalArgumentException("Unhandled rounding method: " + roundingMethod);
+        }
+        return unscaled;
+    }
+
+
+    /**
+     * Computes a number {@code delta} close to {@code originalDelta} with
+     * the property that <pre><code>
+     *   x + delta - x
+     * </code></pre>
+     * is exactly machine-representable.
+     * This is useful when computing numerical derivatives, in order to reduce
+     * roundoff errors.
+     *
+     * @param x Value.
+     * @param originalDelta Offset value.
+     * @return a number {@code delta} so that {@code x + delta} and {@code x}
+     * differ by a representable floating number.
+     */
+    public static double representableDelta(double x,
+                                            double originalDelta) {
+        return x + originalDelta - x;
+    }
+}


Mime
View raw message