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Posted to commits@commons.apache.org by er...@apache.org on 2019/09/27 14:35:11 UTC
[commons-geometry] 01/06: GEOMETRY-61: Improvement of "normalize"
functionality for class "Vector1D".
This is an automated email from the ASF dual-hosted git repository.
erans pushed a commit to branch master
in repository https://gitbox.apache.org/repos/asf/commons-geometry.git
commit 42fb4dc84e61da07d5f32e2304bdeccc540b9a4d
Author: Gilles Sadowski <gi...@harfang.homelinux.org>
AuthorDate: Wed Sep 25 15:01:12 2019 +0200
GEOMETRY-61: Improvement of "normalize" functionality for class "Vector1D".
"Unit" class defines factory methods "from" to create a normalized instance.
---
.../euclidean/oned/AffineTransformMatrix1D.java | 2 +-
.../commons/geometry/euclidean/oned/Vector1D.java | 54 ++++++++++++++--------
.../geometry/euclidean/oned/Vector1DTest.java | 12 ++---
3 files changed, 42 insertions(+), 26 deletions(-)
diff --git a/commons-geometry-euclidean/src/main/java/org/apache/commons/geometry/euclidean/oned/AffineTransformMatrix1D.java b/commons-geometry-euclidean/src/main/java/org/apache/commons/geometry/euclidean/oned/AffineTransformMatrix1D.java
index 1a6aaf9..045c893 100644
--- a/commons-geometry-euclidean/src/main/java/org/apache/commons/geometry/euclidean/oned/AffineTransformMatrix1D.java
+++ b/commons-geometry-euclidean/src/main/java/org/apache/commons/geometry/euclidean/oned/AffineTransformMatrix1D.java
@@ -108,7 +108,7 @@ public final class AffineTransformMatrix1D implements AffineTransformMatrix<Vect
*/
@Override
public Vector1D applyDirection(final Vector1D vec) {
- return applyVector(vec, Vector1D::normalize);
+ return applyVector(vec, Vector1D.Unit::from);
}
/** Get a new transform containing the result of applying a translation logically after
diff --git a/commons-geometry-euclidean/src/main/java/org/apache/commons/geometry/euclidean/oned/Vector1D.java b/commons-geometry-euclidean/src/main/java/org/apache/commons/geometry/euclidean/oned/Vector1D.java
index 4be9515..a750879 100644
--- a/commons-geometry-euclidean/src/main/java/org/apache/commons/geometry/euclidean/oned/Vector1D.java
+++ b/commons-geometry-euclidean/src/main/java/org/apache/commons/geometry/euclidean/oned/Vector1D.java
@@ -33,10 +33,10 @@ public class Vector1D extends EuclideanVector<Vector1D> {
public static final Vector1D ZERO = new Vector1D(0.0);
/** Unit vector (coordinates: 1). */
- public static final Vector1D ONE = new UnitVector(1.0);
+ public static final Vector1D ONE = Unit.ONE;
/** Negation of unit vector (coordinates: -1). */
- public static final Vector1D MINUS_ONE = new UnitVector(-1.0);
+ public static final Vector1D MINUS_ONE = Unit.MINUS_ONE;
// CHECKSTYLE: stop ConstantName
/** A vector with all coordinates set to NaN. */
@@ -99,7 +99,7 @@ public class Vector1D extends EuclideanVector<Vector1D> {
/** {@inheritDoc} */
@Override
public Vector1D directionTo(Vector1D v) {
- return normalize(v.x - x);
+ return vectorTo(v).normalize();
}
/** {@inheritDoc} */
@@ -166,7 +166,7 @@ public class Vector1D extends EuclideanVector<Vector1D> {
/** {@inheritDoc} */
@Override
public Vector1D normalize() {
- return normalize(x);
+ return Unit.from(x);
}
/** {@inheritDoc} */
@@ -291,17 +291,6 @@ public class Vector1D extends EuclideanVector<Vector1D> {
return new Vector1D(x);
}
- /** Returns a normalized vector derived from the given value.
- * @param x abscissa (first coordinate value)
- * @return normalized vector instance
- * @throws IllegalNormException if the norm of the given value is zero, NaN, or infinite
- */
- public static Vector1D normalize(final double x) {
- Vectors.checkedNorm(Vectors.norm(x));
-
- return (x > 0.0) ? ONE : MINUS_ONE;
- }
-
/** Parses the given string and returns a new vector instance. The expected string
* format is the same as that returned by {@link #toString()}.
* @param str the string to parse
@@ -388,7 +377,11 @@ public class Vector1D extends EuclideanVector<Vector1D> {
/** Private class used to represent unit vectors. This allows optimizations to be performed for certain
* operations.
*/
- private static final class UnitVector extends Vector1D {
+ public static final class Unit extends Vector1D {
+ /** Unit vector (coordinates: 1). */
+ static final Unit ONE = new Unit(1d);
+ /** Negation of unit vector (coordinates: -1). */
+ static final Unit MINUS_ONE = new Unit(-1d);
/** Serializable version identifier */
private static final long serialVersionUID = 20180903L;
@@ -397,10 +390,33 @@ public class Vector1D extends EuclideanVector<Vector1D> {
* values represent a normalized vector.
* @param x abscissa (first coordinate value)
*/
- private UnitVector(final double x) {
+ private Unit(final double x) {
super(x);
}
+ /**
+ * Creates a normalized vector.
+ *
+ * @param v Vector.
+ * @return a vector whose norm is 1.
+ * @throws IllegalNormException if the norm of the given value is zero, NaN, or infinite
+ */
+ public static Unit from(double x) {
+ Vectors.checkedNorm(Vectors.norm(x));
+ return x > 0 ? ONE : MINUS_ONE;
+ }
+
+ /**
+ * Creates a normalized vector.
+ *
+ * @param v Vector.
+ * @return a vector whose norm is 1.
+ * @throws IllegalNormException if the norm of the given value is zero, NaN, or infinite
+ */
+ public static Unit from(Vector1D v) {
+ return from(v.getX());
+ }
+
/** {@inheritDoc} */
@Override
public double norm() {
@@ -427,8 +443,8 @@ public class Vector1D extends EuclideanVector<Vector1D> {
/** {@inheritDoc} */
@Override
- public UnitVector negate() {
- return new UnitVector(-getX());
+ public Vector1D negate() {
+ return this == ONE ? MINUS_ONE : ONE;
}
}
}
diff --git a/commons-geometry-euclidean/src/test/java/org/apache/commons/geometry/euclidean/oned/Vector1DTest.java b/commons-geometry-euclidean/src/test/java/org/apache/commons/geometry/euclidean/oned/Vector1DTest.java
index 4583d8b..1b58077 100644
--- a/commons-geometry-euclidean/src/test/java/org/apache/commons/geometry/euclidean/oned/Vector1DTest.java
+++ b/commons-geometry-euclidean/src/test/java/org/apache/commons/geometry/euclidean/oned/Vector1DTest.java
@@ -622,19 +622,19 @@ public class Vector1DTest {
@Test
public void testNormalize_static() {
// act/assert
- checkVector(Vector1D.normalize(2.0), 1);
- checkVector(Vector1D.normalize(-4.0), -1);
+ checkVector(Vector1D.Unit.from(2.0), 1);
+ checkVector(Vector1D.Unit.from(-4.0), -1);
}
@Test
public void testNormalize_static_illegalNorm() {
- GeometryTestUtils.assertThrows(() -> Vector1D.normalize(0.0),
+ GeometryTestUtils.assertThrows(() -> Vector1D.Unit.from(0.0),
IllegalNormException.class);
- GeometryTestUtils.assertThrows(() -> Vector1D.normalize(Double.NaN),
+ GeometryTestUtils.assertThrows(() -> Vector1D.Unit.from(Double.NaN),
IllegalNormException.class);
- GeometryTestUtils.assertThrows(() -> Vector1D.normalize(Double.NEGATIVE_INFINITY),
+ GeometryTestUtils.assertThrows(() -> Vector1D.Unit.from(Double.NEGATIVE_INFINITY),
IllegalNormException.class);
- GeometryTestUtils.assertThrows(() -> Vector1D.normalize(Double.POSITIVE_INFINITY),
+ GeometryTestUtils.assertThrows(() -> Vector1D.Unit.from(Double.POSITIVE_INFINITY),
IllegalNormException.class);
}