Added array constructor and getter for Vector2D and Vector3D.

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/math/trunk@1200546 13f79535-47bb-0310-9956-ffa450edef68

src/main/java/org/apache/commons/math/geometry/euclidean/threed/Vector3D.java

@@ -20,6 +20,7 @@ package org.apache.commons.math.geometry.euclidean.threed;
 import java.io.Serializable;
 import java.text.NumberFormat;
 
+import org.apache.commons.math.exception.DimensionMismatchException;
 import org.apache.commons.math.exception.MathArithmeticException;
 import org.apache.commons.math.exception.util.LocalizedFormats;
 import org.apache.commons.math.geometry.Vector;
@@ -97,6 +98,21 @@ public class Vector3D implements Serializable, Vector<Euclidean3D> {
         this.z = z;
     }
 
+    /** Simple constructor.
+     * Build a vector from its coordinates
+     * @param v coordinates array
+     * @exception DimensionMismatchException if array does not have 3 elements
+     * @see #toArray()
+     */
+    public Vector3D(double[] v) throws DimensionMismatchException {
+        if (v.length != 3) {
+            throw new DimensionMismatchException(v.length, 3);
+        }
+        this.x = v[0];
+        this.y = v[1];
+        this.z = v[2];
+    }
+
     /** Simple constructor.
      * Build a vector from its azimuthal coordinates
      * @param alpha azimuth (&alpha;) around Z
@@ -198,6 +214,14 @@ public class Vector3D implements Serializable, Vector<Euclidean3D> {
         return z;
     }
 
+    /** Get the vector coordinates as a dimension 3 array.
+     * @return vector coordinates
+     * @see #Vector3D(double[])
+     */
+    public double[] toArray() {
+        return new double[] { x, y, z };
+    }
+
     /** {@inheritDoc} */
     public Space getSpace() {
         return Euclidean3D.getInstance();

src/main/java/org/apache/commons/math/geometry/euclidean/twod/Vector2D.java

@@ -18,6 +18,7 @@ package org.apache.commons.math.geometry.euclidean.twod;
 
 import java.text.NumberFormat;
 
+import org.apache.commons.math.exception.DimensionMismatchException;
 import org.apache.commons.math.exception.MathArithmeticException;
 import org.apache.commons.math.exception.util.LocalizedFormats;
 import org.apache.commons.math.geometry.Space;
@@ -69,6 +70,20 @@ public class Vector2D implements Vector<Euclidean2D> {
         this.y = y;
     }
 
+    /** Simple constructor.
+     * Build a vector from its coordinates
+     * @param v coordinates array
+     * @exception DimensionMismatchException if array does not have 2 elements
+     * @see #toArray()
+     */
+    public Vector2D(double[] v) throws DimensionMismatchException {
+        if (v.length != 2) {
+            throw new DimensionMismatchException(v.length, 2);
+        }
+        this.x = v[0];
+        this.y = v[1];
+    }
+
     /** Multiplicative constructor
      * Build a vector from another one and a scale factor.
      * The vector built will be a * u
@@ -143,6 +158,14 @@ public class Vector2D implements Vector<Euclidean2D> {
         return y;
     }
 
+    /** Get the vector coordinates as a dimension 2 array.
+     * @return vector coordinates
+     * @see #Vector2D(double[])
+     */
+    public double[] toArray() {
+        return new double[] { x, y };
+    }
+
     /** {@inheritDoc} */
     public Space getSpace() {
         return Euclidean2D.getInstance();

src/site/xdoc/changes.xml

@@ -52,6 +52,9 @@ The <action> type attribute can be add,update,fix,remove.
     If the output is not quite correct, check for invisible trailing spaces!
      -->
     <release version="3.0" date="TBD" description="TBD">
+      <action dev="luc" type="add" due-to="Jan Kotek" >
+        Added array constructor and getter for Vector2D and Vector3D.
+      </action>
       <action dev="luc" type="add" due-to="Jan Kotek" >
         Added applyTo and applyInverseTo methods in the Rotation class that
         handle directly arrays instead of Vector3D instances.

src/test/java/org/apache/commons/math/geometry/euclidean/threed/Vector3DTest.java

@@ -17,6 +17,7 @@
 
 package org.apache.commons.math.geometry.euclidean.threed;
 
+import org.apache.commons.math.exception.DimensionMismatchException;
 import org.apache.commons.math.exception.MathArithmeticException;
 import org.apache.commons.math.random.Well1024a;
 import org.apache.commons.math.util.FastMath;
@@ -41,6 +42,13 @@ public class Vector3DTest {
                                  5, Vector3D.MINUS_J,
                                  -3, Vector3D.MINUS_K),
                     2, 0, 3);
+        checkVector(new Vector3D(new double[] { 2,  5,  -3 }),
+                    2, 5, -3);
+    }
+
+    @Test(expected=DimensionMismatchException.class)
+    public void testWrongDimension() {
+        new Vector3D(new double[] { 2,  5 });
     }
 
     @Test
@@ -49,6 +57,10 @@ public class Vector3DTest {
         Assert.assertTrue(FastMath.abs(v.getX() - 1) < 1.0e-12);
         Assert.assertTrue(FastMath.abs(v.getY() - 2) < 1.0e-12);
         Assert.assertTrue(FastMath.abs(v.getZ() - 3) < 1.0e-12);
+        double[] coordinates = v.toArray();
+        Assert.assertTrue(FastMath.abs(coordinates[0] - 1) < 1.0e-12);
+        Assert.assertTrue(FastMath.abs(coordinates[1] - 2) < 1.0e-12);
+        Assert.assertTrue(FastMath.abs(coordinates[2] - 3) < 1.0e-12);
     }
 
     @Test