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Posted to commits@commons.apache.org by lu...@apache.org on 2008/02/08 12:22:40 UTC
svn commit: r619836 - in /commons/proper/math/trunk/src:
java/org/apache/commons/math/util/MathUtils.java site/xdoc/changes.xml
test/org/apache/commons/math/util/MathUtilsTest.java
Author: luc
Date: Fri Feb 8 03:22:35 2008
New Revision: 619836
URL: http://svn.apache.org/viewvc?rev=619836&view=rev
Log:
added equals and hash methods for double arrays (supporting null) in MathUtils
Modified:
commons/proper/math/trunk/src/java/org/apache/commons/math/util/MathUtils.java
commons/proper/math/trunk/src/site/xdoc/changes.xml
commons/proper/math/trunk/src/test/org/apache/commons/math/util/MathUtilsTest.java
Modified: commons/proper/math/trunk/src/java/org/apache/commons/math/util/MathUtils.java
URL: http://svn.apache.org/viewvc/commons/proper/math/trunk/src/java/org/apache/commons/math/util/MathUtils.java?rev=619836&r1=619835&r2=619836&view=diff
==============================================================================
--- commons/proper/math/trunk/src/java/org/apache/commons/math/util/MathUtils.java (original)
+++ commons/proper/math/trunk/src/java/org/apache/commons/math/util/MathUtils.java Fri Feb 8 03:22:35 2008
@@ -276,6 +276,30 @@
}
/**
+ * Returns true iff both arguments aren null or have same dimensions
+ * and all their elements are {@link #equals(double,double) equals}
+ *
+ * @param x first array
+ * @param y second array
+ * @return true if the values are both null or have same dimension
+ * and equal elements
+ */
+ public static boolean equals(double[] x, double[] y) {
+ if ((x == null) || (y == null)) {
+ return !((x == null) ^ (y == null));
+ }
+ if (x.length != y.length) {
+ return false;
+ }
+ for (int i = 0; i < x.length; ++i) {
+ if (!equals(x[i], y[i])) {
+ return false;
+ }
+ }
+ return true;
+ }
+
+ /**
* Returns n!. Shorthand for <code>n</code> <a
* href="http://mathworld.wolfram.com/Factorial.html"> Factorial</a>, the
* product of the numbers <code>1,...,n</code>.
@@ -430,6 +454,23 @@
public static int hash(double value) {
long bits = Double.doubleToLongBits(value);
return (int)(bits ^ (bits >>> 32));
+ }
+
+ /**
+ * Returns an integer hash code representing the given double array value.
+ *
+ * @param value the value to be hashed (may be null)
+ * @return the hash code
+ */
+ public static int hash(double[] value) {
+ if (value == null) {
+ return 0;
+ }
+ int result = value.length;
+ for (int i = 0; i < value.length; ++i) {
+ result = result * 31 + hash(value[i]);
+ }
+ return result;
}
/**
Modified: commons/proper/math/trunk/src/site/xdoc/changes.xml
URL: http://svn.apache.org/viewvc/commons/proper/math/trunk/src/site/xdoc/changes.xml?rev=619836&r1=619835&r2=619836&view=diff
==============================================================================
--- commons/proper/math/trunk/src/site/xdoc/changes.xml (original)
+++ commons/proper/math/trunk/src/site/xdoc/changes.xml Fri Feb 8 03:22:35 2008
@@ -143,6 +143,9 @@
Throw EOFException when using empty files with ValueServer in replay and
digest modes.
</action>
+ <action dev="luc" type="update" >
+ Added a equals and hash methods in MathUtils to check for double arrays
+ </action>
</release>
<release version="1.1" date="2005-12-17"
description="This is a maintenance release containing bug fixes and enhancements.
Modified: commons/proper/math/trunk/src/test/org/apache/commons/math/util/MathUtilsTest.java
URL: http://svn.apache.org/viewvc/commons/proper/math/trunk/src/test/org/apache/commons/math/util/MathUtilsTest.java?rev=619836&r1=619835&r2=619836&view=diff
==============================================================================
--- commons/proper/math/trunk/src/test/org/apache/commons/math/util/MathUtilsTest.java (original)
+++ commons/proper/math/trunk/src/test/org/apache/commons/math/util/MathUtilsTest.java Fri Feb 8 03:22:35 2008
@@ -209,6 +209,27 @@
}
}
+ public void testArrayEquals() {
+ assertFalse(MathUtils.equals(new double[] { 1d }, null));
+ assertFalse(MathUtils.equals(null, new double[] { 1d }));
+ assertTrue(MathUtils.equals((double[]) null, (double[]) null));
+
+ assertFalse(MathUtils.equals(new double[] { 1d }, new double[0]));
+ assertTrue(MathUtils.equals(new double[] { 1d }, new double[] { 1d }));
+ assertTrue(MathUtils.equals(new double[] {
+ Double.NaN, Double.POSITIVE_INFINITY,
+ Double.NEGATIVE_INFINITY, 1d, 0d
+ }, new double[] {
+ Double.NaN, Double.POSITIVE_INFINITY,
+ Double.NEGATIVE_INFINITY, 1d, 0d
+ }));
+ assertFalse(MathUtils.equals(new double[] { Double.POSITIVE_INFINITY },
+ new double[] { Double.NEGATIVE_INFINITY }));
+ assertFalse(MathUtils.equals(new double[] { 1d },
+ new double[] { MathUtils.nextAfter(1d, 2d) }));
+
+ }
+
public void testFactorial() {
for (int i = 1; i < 10; i++) {
assertEquals(i + "! ", factorial(i), MathUtils.factorial(i));
@@ -293,6 +314,22 @@
}
}
}
+ }
+
+ public void testArrayHash() {
+ assertEquals(0, MathUtils.hash((double[]) null));
+ assertEquals(MathUtils.hash(new double[] {
+ Double.NaN, Double.POSITIVE_INFINITY,
+ Double.NEGATIVE_INFINITY, 1d, 0d
+ }),
+ MathUtils.hash(new double[] {
+ Double.NaN, Double.POSITIVE_INFINITY,
+ Double.NEGATIVE_INFINITY, 1d, 0d
+ }));
+ assertFalse(MathUtils.hash(new double[] { 1d }) ==
+ MathUtils.hash(new double[] { MathUtils.nextAfter(1d, 2d) }));
+ assertFalse(MathUtils.hash(new double[] { 1d }) ==
+ MathUtils.hash(new double[] { 1d, 1d }));
}
public void testIndicatorByte() {