Author: erans
Date: Thu Mar 17 10:38:19 2011
New Revision: 1082442
URL: http://svn.apache.org/viewvc?rev=1082442&view=rev
Log:
MATH-545
Added "cosine" method in "RealVector" interface and default implementation
in "AbstractRealVector".
Modified:
commons/proper/math/trunk/src/main/java/org/apache/commons/math/linear/AbstractRealVector.java
commons/proper/math/trunk/src/main/java/org/apache/commons/math/linear/RealVector.java
commons/proper/math/trunk/src/site/xdoc/changes.xml
commons/proper/math/trunk/src/test/java/org/apache/commons/math/linear/ArrayRealVectorTest.java
Modified:
commons/proper/math/trunk/src/main/java/org/apache/commons/math/linear/AbstractRealVector.java
URL:
http://svn.apache.org/viewvc/commons/proper/math/trunk/src/main/java/org/apache/commons/math/linear/AbstractRealVector.java?rev=1082442&r1=1082441&r2=1082442&view=diff
==============================================================================
---
commons/proper/math/trunk/src/main/java/org/apache/commons/math/linear/AbstractRealVector.java
(original)
+++
commons/proper/math/trunk/src/main/java/org/apache/commons/math/linear/AbstractRealVector.java
Thu Mar 17 10:38:19 2011
@@ -23,6 +23,7 @@ import java.util.NoSuchElementException;
import org.apache.commons.math.exception.MathUnsupportedOperationException;
import org.apache.commons.math.exception.DimensionMismatchException;
import org.apache.commons.math.exception.OutOfRangeException;
+import org.apache.commons.math.exception.MathArithmeticException;
import org.apache.commons.math.analysis.FunctionUtils;
import org.apache.commons.math.analysis.function.Add;
import org.apache.commons.math.analysis.function.Multiply;
@@ -184,6 +185,23 @@ public abstract class AbstractRealVector
}
/** {@inheritDoc} */
+ public double cosine(RealVector v) {
+ final double norm = getNorm();
+ final double vNorm = v.getNorm();
+
+ if (norm == 0 ||
+ vNorm == 0) {
+ throw new MathArithmeticException(LocalizedFormats.ZERO_NORM);
+ }
+ return dotProduct(v) / (norm * vNorm);
+ }
+
+ /** {@inheritDoc} */
+ public double cosine(double[] v) {
+ return cosine(new ArrayRealVector(v, false));
+ }
+
+ /** {@inheritDoc} */
public RealVector ebeDivide(double[] v) {
return ebeDivide(new ArrayRealVector(v, false));
}
Modified:
commons/proper/math/trunk/src/main/java/org/apache/commons/math/linear/RealVector.java
URL:
http://svn.apache.org/viewvc/commons/proper/math/trunk/src/main/java/org/apache/commons/math/linear/RealVector.java?rev=1082442&r1=1082441&r2=1082442&view=diff
==============================================================================
---
commons/proper/math/trunk/src/main/java/org/apache/commons/math/linear/RealVector.java
(original)
+++
commons/proper/math/trunk/src/main/java/org/apache/commons/math/linear/RealVector.java
Thu Mar 17 10:38:19 2011
@@ -307,6 +307,24 @@ public interface RealVector {
double dotProduct(double[] v);
/**
+ * Computes the cosine of the angle between this vector and the
+ * argument.
+ *
+ * @param v Vector.
+ * @return the cosine of the angle between this vector and {@code v}.
+ */
+ double cosine(RealVector v);
+
+ /**
+ * Computes the cosine of the angle between this vector and the
+ * vector whose components are given as argument.
+ *
+ * @param v Components of a vector.
+ * @return the cosine of the angle between this vector and {@code v}.
+ */
+ double cosine(double[] v);
+
+ /**
* Returns the L<sub>2</sub> norm of the vector.
* <p>The L<sub>2</sub> norm is the root of the sum of
* the squared elements.</p>
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=1082442&r1=1082441&r2=1082442&view=diff
==============================================================================
--- commons/proper/math/trunk/src/site/xdoc/changes.xml (original)
+++ commons/proper/math/trunk/src/site/xdoc/changes.xml Thu Mar 17 10:38:19 2011
@@ -52,6 +52,10 @@ The <action> type attribute can be add,u
If the output is not quite correct, check for invisible trailing spaces!
-->
<release version="3.0" date="TBD" description="TBD">
+ <action dev="erans" type="update" issue="MATH-545">
+ Added "cosine" method in "RealVector" interface and default
implementation
+ in "AbstractRealVector".
+ </action>
<action dev="erans" type="fix" issue="MATH-546" due-to="Nate Paymer">
Fixed bug in "KMeansPlusPlusClusterer".
</action>
Modified:
commons/proper/math/trunk/src/test/java/org/apache/commons/math/linear/ArrayRealVectorTest.java
URL:
http://svn.apache.org/viewvc/commons/proper/math/trunk/src/test/java/org/apache/commons/math/linear/ArrayRealVectorTest.java?rev=1082442&r1=1082441&r2=1082442&view=diff
==============================================================================
---
commons/proper/math/trunk/src/test/java/org/apache/commons/math/linear/ArrayRealVectorTest.java
(original)
+++
commons/proper/math/trunk/src/test/java/org/apache/commons/math/linear/ArrayRealVectorTest.java
Thu Mar 17 10:38:19 2011
@@ -27,6 +27,7 @@ import org.apache.commons.math.util.Fast
import org.apache.commons.math.exception.OutOfRangeException;
import org.apache.commons.math.exception.MathIllegalArgumentException;
import org.apache.commons.math.exception.MathArithmeticException;
+import org.apache.commons.math.exception.DimensionMismatchException;
import org.apache.commons.math.analysis.function.Abs;
import org.apache.commons.math.analysis.function.Acos;
import org.apache.commons.math.analysis.function.Asin;
@@ -221,6 +222,14 @@ public class ArrayRealVectorTest {
return dot;
}
+ public double cosine(RealVector v) {
+ throw unsupported();
+ }
+
+ public double cosine(double[] v) {
+ throw unsupported();
+ }
+
public double getNorm() {
throw unsupported();
}
@@ -1137,6 +1146,49 @@ public class ArrayRealVectorTest {
Assert.assertTrue(Double.isNaN(v4.getMaxValue()));
}
+ @Test
+ public void testCosine() {
+ final ArrayRealVector v = new ArrayRealVector(new double[] {1, 0, 0});
+
+ double[] wData = new double[] {1, 1, 0};
+ RealVector w = new ArrayRealVector(wData);
+ Assert.assertEquals(FastMath.sqrt(2) / 2, v.cosine(wData),
normTolerance);
+ Assert.assertEquals(FastMath.sqrt(2) / 2, v.cosine(w), normTolerance);
+
+ wData = new double[] {1, 0, 0};
+ w = new ArrayRealVector(wData);
+ Assert.assertEquals(1, v.cosine(wData), normTolerance);
+ Assert.assertEquals(1, v.cosine(w), normTolerance);
+
+ wData = new double[] {0, 1, 0};
+ w = new ArrayRealVector(wData);
+ Assert.assertEquals(0, v.cosine(wData), normTolerance);
+ Assert.assertEquals(0, v.cosine(w), 0);
+
+ wData = new double[] {-1, 0, 0};
+ w = new ArrayRealVector(wData);
+ Assert.assertEquals(-1, v.cosine(wData), normTolerance);
+ Assert.assertEquals(-1, v.cosine(w), normTolerance);
+ }
+
+ @Test(expected=MathArithmeticException.class)
+ public void testCosinePrecondition1() {
+ final ArrayRealVector v = new ArrayRealVector(new double[] {0, 0, 0});
+ final ArrayRealVector w = new ArrayRealVector(new double[] {1, 0, 0});
+ v.cosine(w);
+ }
+ @Test(expected=MathArithmeticException.class)
+ public void testCosinePrecondition2() {
+ final ArrayRealVector v = new ArrayRealVector(new double[] {0, 0, 0});
+ final ArrayRealVector w = new ArrayRealVector(new double[] {1, 0, 0});
+ w.cosine(v);
+ }
+ @Test(expected=DimensionMismatchException.class)
+ public void testCosinePrecondition3() {
+ final ArrayRealVector v = new ArrayRealVector(new double[] {1, 2, 3});
+ final ArrayRealVector w = new ArrayRealVector(new double[] {1, 2, 3,
4});
+ v.cosine(w);
+ }
/** verifies that two vectors are close (sup norm) */
protected void assertClose(String msg, double[] m, double[] n,
