Rotation.java
| Index Score | ||
|---|---|---|
 |
 |
org.apache.commons.math.geometry |
 |
 |
Commons Math |
View: Reasons, Metrics, Source Code
These are the metrics that contribute to the Enerjy Score for this file, ranked by impact. So the metrics listed at the top influence the score to a greater extent that the metrics listed at the bottom.
| Metric | Description | |
|---|---|---|
| LINE_COMMENT | Number of line comments |  |
| EXEC_COMMENTS | Comments in executable code | |
| SIZE | Size of the file in bytes | |
| OPERANDS | Number of operands | |
| PROGRAM_LENGTH | Halstead program length | |
| OPERATORS | Number of operators | |
| COMPARISONS | Number of comparison operators | |
| COMMENTS | Comment lines | |
| JAVA0076 | JAVA0076 Use of magic number | |
| DOC_COMMENT | Number of javadoc comment lines | |
| LINES | Number of lines in the source file | |
| LOGICAL_LINES | Number of statements | |
| ELOC | Effective lines of code | |
| LOC | Lines of code | |
| JAVA0078 | JAVA0078 Floating point values compared with == | |
| DECL_COMMENTS | Comments in declarations | |
| RETURNS | Number of return points from functions | |
| UNIQUE_OPERANDS | Number of unique operands | |
| PROGRAM_VOCAB | Halstead program vocabulary | |
| CYCLOMATIC | Cyclomatic complexity | |
| INTERFACE_COMPLEXITY | Interface complexity | |
| JAVA0034 | JAVA0034 Missing braces in if statement | |
| BLOCKS | Number of blocks | |
| JAVA0117 | JAVA0117 Missing javadoc: method 'method' | |
| PROGRAM_VOLUME | Halstead program volume | |
| JAVA0136 | JAVA0136 N methods defined in class (maximum: M) | |
| JAVA0126 | JAVA0126 Method declares unchecked exception in throws | |
| WHITESPACE | Number of whitespace lines | |
| JAVA0110 | JAVA0110 Incorrect javadoc: no @return tag | |
| LOOPS | Number of loops | |
| JAVA0108 | JAVA0108 Incorrect javadoc: no @param tag for 'parameter' | |
| UNIQUE_OPERATORS | Number of unique operators | |
| JAVA0130 | JAVA0130 Non-static method does not use instance fields | |
| JAVA0145 | JAVA0145 Tab character used in source file | |
/*
* 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.math.geometry;
import java.io.Serializable;
/**
* This class implements rotations in a three-dimensional space.
*
* <p>Rotations can be represented by several different mathematical
* entities (matrices, axe and angle, Cardan or Euler angles,
* quaternions). This class presents an higher level abstraction, more
* user-oriented and hiding this implementation details. Well, for the
* curious, we use quaternions for the internal representation. The
* user can build a rotation from any of these representations, and
* any of these representations can be retrieved from a
* <code>Rotation</code> instance (see the various constructors and
* getters). In addition, a rotation can also be built implicitely
* from a set of vectors and their image.</p>
* <p>This implies that this class can be used to convert from one
* representation to another one. For example, converting a rotation
* matrix into a set of Cardan angles from can be done using the
* followong single line of code:</p>
* <pre>
* double[] angles = new Rotation(matrix, 1.0e-10).getAngles(RotationOrder.XYZ);
* </pre>
* <p>Focus is oriented on what a rotation <em>do</em> rather than on its
* underlying representation. Once it has been built, and regardless of its
* internal representation, a rotation is an <em>operator</em> which basically
* transforms three dimensional {@link Vector3D vectors} into other three
* dimensional {@link Vector3D vectors}. Depending on the application, the
* meaning of these vectors may vary and the semantics of the rotation also.</p>
* <p>For example in an spacecraft attitude simulation tool, users will often
* consider the vectors are fixed (say the Earth direction for example) and the
* rotation transforms the coordinates coordinates of this vector in inertial
* frame into the coordinates of the same vector in satellite frame. In this
* case, the rotation implicitely defines the relation between the two frames.
* Another example could be a telescope control application, where the rotation
* would transform the sighting direction at rest into the desired observing
* direction when the telescope is pointed towards an object of interest. In this
* case the rotation transforms the directionf at rest in a topocentric frame
* into the sighting direction in the same topocentric frame. In many case, both
* approaches will be combined, in our telescope example, we will probably also
* need to transform the observing direction in the topocentric frame into the
* observing direction in inertial frame taking into account the observatory
* location and the Earth rotation.</p>
*
* <p>These examples show that a rotation is what the user wants it to be, so this
* class does not push the user towards one specific definition and hence does not
* provide methods like <code>projectVectorIntoDestinationFrame</code> or
* <code>computeTransformedDirection</code>. It provides simpler and more generic
* methods: {@link #applyTo(Vector3D) applyTo(Vector3D)} and {@link
* #applyInverseTo(Vector3D) applyInverseTo(Vector3D)}.</p>
*
* <p>Since a rotation is basically a vectorial operator, several rotations can be
* composed together and the composite operation <code>r = r<sub>1</sub> o
* r<sub>2</sub></code> (which means that for each vector <code>u</code>,
* <code>r(u) = r<sub>1</sub>(r<sub>2</sub>(u))</code>) is also a rotation. Hence
* we can consider that in addition to vectors, a rotation can be applied to other
* rotations as well (or to itself). With our previous notations, we would say we
* can apply <code>r<sub>1</sub></code> to <code>r<sub>2</sub></code> and the result
* we get is <code>r = r<sub>1</sub> o r<sub>2</sub></code>. For this purpose, the
* class provides the methods: {@link #applyTo(Rotation) applyTo(Rotation)} and
* {@link #applyInverseTo(Rotation) applyInverseTo(Rotation)}.</p>
*
* <p>Rotations are guaranteed to be immutable objects.</p>
*
* @version $Revision: 627994 $ $Date: 2008-02-15 05:16:05 -0500 (Fri, 15 Feb 2008) $
* @see Vector3D
* @see RotationOrder
* @since 1.2
*/
public class Rotation implements Serializable {
/** Build the identity rotation.
*/
public Rotation() {
q0 = 1;
q1 = 0;
q2 = 0;
q3 = 0;
}
/** Build a rotation from the quaternion coordinates.
* <p>A rotation can be built from a <em>normalized</em> quaternion,
* i.e. a quaternion for which q<sub>0</sub><sup>2</sup> +
* q<sub>1</sub><sup>2</sup> + q<sub>2</sub><sup>2</sup> +
* q<sub>3</sub><sup>2</sup> = 1. If the quaternion is not normalized,
* the constructor can normalize it in a preprocessing step.</p>
* @param q0 scalar part of the quaternion
* @param q1 first coordinate of the vectorial part of the quaternion
* @param q2 second coordinate of the vectorial part of the quaternion
* @param q3 third coordinate of the vectorial part of the quaternion
* @param needsNormalization if true, the coordinates are considered
* not to be normalized, a normalization preprocessing step is performed
* before using them
*/
public Rotation(double q0, double q1, double q2, double q3,
boolean needsNormalization) {
if (needsNormalization) {
// normalization preprocessing
double inv = 1.0 / Math.sqrt(q0 * q0 + q1 * q1 + q2 * q2 + q3 * q3);
q0 *= inv;
q1 *= inv;
q2 *= inv;
q3 *= inv;
}
this.q0 = q0;
this.q1 = q1;
this.q2 = q2;
this.q3 = q3;
}
/** Build a rotation from an axis and an angle.
* <p>We use the convention that angles are oriented according to
* the effect of the rotation on vectors around the axis. That means
* that if (i, j, k) is a direct frame and if we first provide +k as
* the axis and PI/2 as the angle to this constructor, and then
* {@link #applyTo(Vector3D) apply} the instance to +i, we will get
* +j.</p>
* @param axis axis around which to rotate
* @param angle rotation angle.
* @exception ArithmeticException if the axis norm is zero
*/
public Rotation(Vector3D axis, double angle) {
double norm = axis.getNorm();
if (norm == 0) {
throw new ArithmeticException("zero norm for rotation axis");
}
double halfAngle = -0.5 * angle;
double coeff = Math.sin(halfAngle) / norm;
q0 = Math.cos (halfAngle);
q1 = coeff * axis.getX();
q2 = coeff * axis.getY();
q3 = coeff * axis.getZ();
}
/** Build a rotation from a 3X3 matrix.
* <p>Rotation matrices are orthogonal matrices, i.e. unit matrices
* (which are matrices for which m.m<sup>T</sup> = I) with real
* coefficients. The module of the determinant of unit matrices is
* 1, among the orthogonal 3X3 matrices, only the ones having a
* positive determinant (+1) are rotation matrices.</p>
* <p>When a rotation is defined by a matrix with truncated values
* (typically when it is extracted from a technical sheet where only
* four to five significant digits are available), the matrix is not
* orthogonal anymore. This constructor handles this case
* transparently by using a copy of the given matrix and applying a
* correction to the copy in order to perfect its orthogonality. If
* the Frobenius norm of the correction needed is above the given
* threshold, then the matrix is considered to be too far from a
* true rotation matrix and an exception is thrown.<p>
* @param m rotation matrix
* @param threshold convergence threshold for the iterative
* orthogonality correction (convergence is reached when the
* difference between two steps of the Frobenius norm of the
* correction is below this threshold)
* @exception NotARotationMatrixException if the matrix is not a 3X3
* matrix, or if it cannot be transformed into an orthogonal matrix
* with the given threshold, or if the determinant of the resulting
* orthogonal matrix is negative
*/
public Rotation(double[][] m, double threshold)
throws NotARotationMatrixException {
// dimension check
if ((m.length != 3) || (m[0].length != 3) ||
(m[1].length != 3) || (m[2].length != 3)) {
throw new NotARotationMatrixException("a {0}x{1} matrix" +
" cannot be a rotation matrix",
new Object[] {
Integer.toString(m.length),
Integer.toString(m[0].length)
});
}
// compute a "close" orthogonal matrix
double[][] ort = orthogonalizeMatrix(m, threshold);
// check the sign of the determinant
double det = ort[0][0] * (ort[1][1] * ort[2][2] - ort[2][1] * ort[1][2]) -
ort[1][0] * (ort[0][1] * ort[2][2] - ort[2][1] * ort[0][2]) +
ort[2][0] * (ort[0][1] * ort[1][2] - ort[1][1] * ort[0][2]);
if (det < 0.0) {
throw new NotARotationMatrixException("the closest orthogonal matrix" +
" has a negative determinant {0}",
new Object[] {
Double.toString(det)
});
}
// There are different ways to compute the quaternions elements
// from the matrix. They all involve computing one element from
// the diagonal of the matrix, and computing the three other ones
// using a formula involving a division by the first element,
// which unfortunately can be zero. Since the norm of the
// quaternion is 1, we know at least one element has an absolute
// value greater or equal to 0.5, so it is always possible to
// select the right formula and avoid division by zero and even
// numerical inaccuracy. Checking the elements in turn and using
// the first one greater than 0.45 is safe (this leads to a simple
// test since qi = 0.45 implies 4 qi^2 - 1 = -0.19)
double s = ort[0][0] + ort[1][1] + ort[2][2];
if (s > -0.19) {
// compute q0 and deduce q1, q2 and q3
q0 = 0.5 * Math.sqrt(s + 1.0);
double inv = 0.25 / q0;
q1 = inv * (ort[1][2] - ort[2][1]);
q2 = inv * (ort[2][0] - ort[0][2]);
q3 = inv * (ort[0][1] - ort[1][0]);
} else {
s = ort[0][0] - ort[1][1] - ort[2][2];
if (s > -0.19) {
// compute q1 and deduce q0, q2 and q3
q1 = 0.5 * Math.sqrt(s + 1.0);
double inv = 0.25 / q1;
q0 = inv * (ort[1][2] - ort[2][1]);
q2 = inv * (ort[0][1] + ort[1][0]);
q3 = inv * (ort[0][2] + ort[2][0]);
} else {
s = ort[1][1] - ort[0][0] - ort[2][2];
if (s > -0.19) {
// compute q2 and deduce q0, q1 and q3
q2 = 0.5 * Math.sqrt(s + 1.0);
double inv = 0.25 / q2;
q0 = inv * (ort[2][0] - ort[0][2]);
q1 = inv * (ort[0][1] + ort[1][0]);
q3 = inv * (ort[2][1] + ort[1][2]);
} else {
// compute q3 and deduce q0, q1 and q2
s = ort[2][2] - ort[0][0] - ort[1][1];
q3 = 0.5 * Math.sqrt(s + 1.0);
double inv = 0.25 / q3;
q0 = inv * (ort[0][1] - ort[1][0]);
q1 = inv * (ort[0][2] + ort[2][0]);
q2 = inv * (ort[2][1] + ort[1][2]);
}
}
}
}
/** Build the rotation that transforms a pair of vector into another pair.
* <p>Except for possible scale factors, if the instance were applied to
* the pair (u<sub>1</sub>, u<sub>2</sub>) it will produce the pair
* (v<sub>1</sub>, v<sub>2</sub>).</p>
* <p>If the angular separation between u<sub>1</sub> and u<sub>2</sub> is
* not the same as the angular separation between v<sub>1</sub> and
* v<sub>2</sub>, then a corrected v'<sub>2</sub> will be used rather than
* v<sub>2</sub>, the corrected vector will be in the (v<sub>1</sub>,
* v<sub>2</sub>) plane.</p>
* @param u1 first vector of the origin pair
* @param u2 second vector of the origin pair
* @param v1 desired image of u1 by the rotation
* @param v2 desired image of u2 by the rotation
* @exception IllegalArgumentException if the norm of one of the vectors is zero
*/
public Rotation(Vector3D u1, Vector3D u2, Vector3D v1, Vector3D v2) {
// norms computation
double u1u1 = Vector3D.dotProduct(u1, u1);
double u2u2 = Vector3D.dotProduct(u2, u2);
double v1v1 = Vector3D.dotProduct(v1, v1);
double v2v2 = Vector3D.dotProduct(v2, v2);
if ((u1u1 == 0) || (u2u2 == 0) || (v1v1 == 0) || (v2v2 == 0)) {
throw new IllegalArgumentException("zero norm for rotation defining vector");
}
double u1x = u1.getX();
double u1y = u1.getY();
double u1z = u1.getZ();
double u2x = u2.getX();
double u2y = u2.getY();
double u2z = u2.getZ();
// normalize v1 in order to have (v1'|v1') = (u1|u1)
double coeff = Math.sqrt (u1u1 / v1v1);
double v1x = coeff * v1.getX();
double v1y = coeff * v1.getY();
double v1z = coeff * v1.getZ();
v1 = new Vector3D(v1x, v1y, v1z);
// adjust v2 in order to have (u1|u2) = (v1|v2) and (v2'|v2') = (u2|u2)
double u1u2 = Vector3D.dotProduct(u1, u2);
double v1v2 = Vector3D.dotProduct(v1, v2);
double coeffU = u1u2 / u1u1;
double coeffV = v1v2 / u1u1;
double beta = Math.sqrt((u2u2 - u1u2 * coeffU) / (v2v2 - v1v2 * coeffV));
double alpha = coeffU - beta * coeffV;
double v2x = alpha * v1x + beta * v2.getX();
double v2y = alpha * v1y + beta * v2.getY();
double v2z = alpha * v1z + beta * v2.getZ();
v2 = new Vector3D(v2x, v2y, v2z);
// preliminary computation (we use explicit formulation instead
// of relying on the Vector3D class in order to avoid building lots
// of temporary objects)
Vector3D uRef = u1;
Vector3D vRef = v1;
double dx1 = v1x - u1.getX();
double dy1 = v1y - u1.getY();
double dz1 = v1z - u1.getZ();
double dx2 = v2x - u2.getX();
double dy2 = v2y - u2.getY();
double dz2 = v2z - u2.getZ();
Vector3D k = new Vector3D(dy1 * dz2 - dz1 * dy2,
dz1 * dx2 - dx1 * dz2,
dx1 * dy2 - dy1 * dx2);
double c = k.getX() * (u1y * u2z - u1z * u2y) +
k.getY() * (u1z * u2x - u1x * u2z) +
k.getZ() * (u1x * u2y - u1y * u2x);
if (c == 0) {
// the (q1, q2, q3) vector is in the (u1, u2) plane
// we try other vectors
Vector3D u3 = Vector3D.crossProduct(u1, u2);
Vector3D v3 = Vector3D.crossProduct(v1, v2);
double u3x = u3.getX();
double u3y = u3.getY();
double u3z = u3.getZ();
double v3x = v3.getX();
double v3y = v3.getY();
double v3z = v3.getZ();
double dx3 = v3x - u3x;
double dy3 = v3y - u3y;
double dz3 = v3z - u3z;
k = new Vector3D(dy1 * dz3 - dz1 * dy3,
dz1 * dx3 - dx1 * dz3,
dx1 * dy3 - dy1 * dx3);
c = k.getX() * (u1y * u3z - u1z * u3y) +
k.getY() * (u1z * u3x - u1x * u3z) +
k.getZ() * (u1x * u3y - u1y * u3x);
if (c == 0) {
// the (q1, q2, q3) vector is aligned with u1:
// we try (u2, u3) and (v2, v3)
k = new Vector3D(dy2 * dz3 - dz2 * dy3,
dz2 * dx3 - dx2 * dz3,
dx2 * dy3 - dy2 * dx3);
c = k.getX() * (u2y * u3z - u2z * u3y) +
k.getY() * (u2z * u3x - u2x * u3z) +
k.getZ() * (u2x * u3y - u2y * u3x);
if (c == 0) {
// the (q1, q2, q3) vector is aligned with everything
// this is really the identity rotation
q0 = 1.0;
q1 = 0.0;
q2 = 0.0;
q3 = 0.0;
return;
}
// we will have to use u2 and v2 to compute the scalar part
uRef = u2;
vRef = v2;
}
}
// compute the vectorial part
c = Math.sqrt(c);
double inv = 1.0 / (c + c);
q1 = inv * k.getX();
q2 = inv * k.getY();
q3 = inv * k.getZ();
// compute the scalar part
k = new Vector3D(uRef.getY() * q3 - uRef.getZ() * q2,
uRef.getZ() * q1 - uRef.getX() * q3,
uRef.getX() * q2 - uRef.getY() * q1);
c = Vector3D.dotProduct(k, k);
q0 = Vector3D.dotProduct(vRef, k) / (c + c);
}
/** Build one of the rotations that transform one vector into another one.
* <p>Except for a possible scale factor, if the instance were
* applied to the vector u it will produce the vector v. There is an
* infinite number of such rotations, this constructor choose the
* one with the smallest associated angle (i.e. the one whose axis
* is orthogonal to the (u, v) plane). If u and v are colinear, an
* arbitrary rotation axis is chosen.</p>
* @param u origin vector
* @param v desired image of u by the rotation
* @exception IllegalArgumentException if the norm of one of the vectors is zero
*/
public Rotation(Vector3D u, Vector3D v) {
double normProduct = u.getNorm() * v.getNorm();
if (normProduct == 0) {
throw new IllegalArgumentException("zero norm for rotation defining vector");
}
double dot = Vector3D.dotProduct(u, v);
if (dot < ((2.0e-15 - 1.0) * normProduct)) {
// special case u = -v: we select a PI angle rotation around
// an arbitrary vector orthogonal to u
Vector3D w = u.orthogonal();
q0 = 0.0;
q1 = -w.getX();
q2 = -w.getY();
q3 = -w.getZ();
} else {
// general case: (u, v) defines a plane, we select
// the shortest possible rotation: axis orthogonal to this plane
q0 = Math.sqrt(0.5 * (1.0 + dot / normProduct));
double coeff = 1.0 / (2.0 * q0 * normProduct);
q1 = coeff * (v.getY() * u.getZ() - v.getZ() * u.getY());
q2 = coeff * (v.getZ() * u.getX() - v.getX() * u.getZ());
q3 = coeff * (v.getX() * u.getY() - v.getY() * u.getX());
}
}
/** Build a rotation from three Cardan or Euler elementary rotations.
* <p>Cardan rotations are three successive rotations around the
* canonical axes X, Y and Z, each axis beeing used once. There are
* 6 such sets of rotations (XYZ, XZY, YXZ, YZX, ZXY and ZYX). Euler
* rotations are three successive rotations around the canonical
* axes X, Y and Z, the first and last rotations beeing around the
* same axis. There are 6 such sets of rotations (XYX, XZX, YXY,
* YZY, ZXZ and ZYZ), the most popular one being ZXZ.</p>
* <p>Beware that many people routinely use the term Euler angles even
* for what really are Cardan angles (this confusion is especially
* widespread in the aerospace business where Roll, Pitch and Yaw angles
* are often wrongly tagged as Euler angles).</p>
* @param order order of rotations to use
* @param alpha1 angle of the first elementary rotation
* @param alpha2 angle of the second elementary rotation
* @param alpha3 angle of the third elementary rotation
*/
public Rotation(RotationOrder order,
double alpha1, double alpha2, double alpha3) {
Rotation r1 = new Rotation(order.getA1(), alpha1);
Rotation r2 = new Rotation(order.getA2(), alpha2);
Rotation r3 = new Rotation(order.getA3(), alpha3);
Rotation composed = r1.applyTo(r2.applyTo(r3));
q0 = composed.q0;
q1 = composed.q1;
q2 = composed.q2;
q3 = composed.q3;
}
/** Revert a rotation.
* Build a rotation which reverse the effect of another
* rotation. This means that if r(u) = v, then r.revert(v) = u. The
* instance is not changed.
* @return a new rotation whose effect is the reverse of the effect
* of the instance
*/
public Rotation revert() {
return new Rotation(-q0, q1, q2, q3, false);
}
/** Get the scalar coordinate of the quaternion.
* @return scalar coordinate of the quaternion
*/
public double getQ0() {
return q0;
}
/** Get the first coordinate of the vectorial part of the quaternion.
* @return first coordinate of the vectorial part of the quaternion
*/
public double getQ1() {
return q1;
}
/** Get the second coordinate of the vectorial part of the quaternion.
* @return second coordinate of the vectorial part of the quaternion
*/
public double getQ2() {
return q2;
}
/** Get the third coordinate of the vectorial part of the quaternion.
* @return third coordinate of the vectorial part of the quaternion
*/
public double getQ3() {
return q3;
}
/** Get the normalized axis of the rotation.
* @return normalized axis of the rotation
*/
public Vector3D getAxis() {
double squaredSine = q1 * q1 + q2 * q2 + q3 * q3;
if (squaredSine == 0) {
return new Vector3D(1, 0, 0);
} else if (q0 < 0) {
double inverse = 1 / Math.sqrt(squaredSine);
return new Vector3D(q1 * inverse, q2 * inverse, q3 * inverse);
}
double inverse = -1 / Math.sqrt(squaredSine);
return new Vector3D(q1 * inverse, q2 * inverse, q3 * inverse);
}
/** Get the angle of the rotation.
* @return angle of the rotation (between 0 and π)
*/
public double getAngle() {
if ((q0 < -0.1) || (q0 > 0.1)) {
return 2 * Math.asin(Math.sqrt(q1 * q1 + q2 * q2 + q3 * q3));
} else if (q0 < 0) {
return 2 * Math.acos(-q0);
}
return 2 * Math.acos(q0);
}
/** Get the Cardan or Euler angles corresponding to the instance.
* <p>The equations show that each rotation can be defined by two
* different values of the Cardan or Euler angles set. For example
* if Cardan angles are used, the rotation defined by the angles
* a<sub>1</sub>, a<sub>2</sub> and a<sub>3</sub> is the same as
* the rotation defined by the angles π + a<sub>1</sub>, π
* - a<sub>2</sub> and π + a<sub>3</sub>. This method implements
* the following arbitrary choices:</p>
* <ul>
* <li>for Cardan angles, the chosen set is the one for which the
* second angle is between -π/2 and π/2 (i.e its cosine is
* positive),</li>
* <li>for Euler angles, the chosen set is the one for which the
* second angle is between 0 and π (i.e its sine is positive).</li>
* </ul>
* <p>Cardan and Euler angle have a very disappointing drawback: all
* of them have singularities. This means that if the instance is
* too close to the singularities corresponding to the given
* rotation order, it will be impossible to retrieve the angles. For
* Cardan angles, this is often called gimbal lock. There is
* <em>nothing</em> to do to prevent this, it is an intrinsic problem
* with Cardan and Euler representation (but not a problem with the
* rotation itself, which is perfectly well defined). For Cardan
* angles, singularities occur when the second angle is close to
* -π/2 or +π/2, for Euler angle singularities occur when the
* second angle is close to 0 or π, this implies that the identity
* rotation is always singular for Euler angles!</p>
* @param order rotation order to use
* @return an array of three angles, in the order specified by the set
* @exception CardanEulerSingularityException if the rotation is
* singular with respect to the angles set specified
*/
public double[] getAngles(RotationOrder order)
throws CardanEulerSingularityException {
if (order == RotationOrder.XYZ) {
// r (Vector3D.plusK) coordinates are :
// sin (theta), -cos (theta) sin (phi), cos (theta) cos (phi)
// (-r) (Vector3D.plusI) coordinates are :
// cos (psi) cos (theta), -sin (psi) cos (theta), sin (theta)
// and we can choose to have theta in the interval [-PI/2 ; +PI/2]
Vector3D v1 = applyTo(Vector3D.plusK);
Vector3D v2 = applyInverseTo(Vector3D.plusI);
if ((v2.getZ() < -0.9999999999) || (v2.getZ() > 0.9999999999)) {
throw new CardanEulerSingularityException(true);
}
return new double[] {
Math.atan2(-(v1.getY()), v1.getZ()),
Math.asin(v2.getZ()),
Math.atan2(-(v2.getY()), v2.getX())
};
} else if (order == RotationOrder.XZY) {
// r (Vector3D.plusJ) coordinates are :
// -sin (psi), cos (psi) cos (phi), cos (psi) sin (phi)
// (-r) (Vector3D.plusI) coordinates are :
// cos (theta) cos (psi), -sin (psi), sin (theta) cos (psi)
// and we can choose to have psi in the interval [-PI/2 ; +PI/2]
Vector3D v1 = applyTo(Vector3D.plusJ);
Vector3D v2 = applyInverseTo(Vector3D.plusI);
if ((v2.getY() < -0.9999999999) || (v2.getY() > 0.9999999999)) {
throw new CardanEulerSingularityException(true);
}
return new double[] {
Math.atan2(v1.getZ(), v1.getY()),
-Math.asin(v2.getY()),
Math.atan2(v2.getZ(), v2.getX())
};
} else if (order == RotationOrder.YXZ) {
// r (Vector3D.plusK) coordinates are :
// cos (phi) sin (theta), -sin (phi), cos (phi) cos (theta)
// (-r) (Vector3D.plusJ) coordinates are :
// sin (psi) cos (phi), cos (psi) cos (phi), -sin (phi)
// and we can choose to have phi in the interval [-PI/2 ; +PI/2]
Vector3D v1 = applyTo(Vector3D.plusK);
Vector3D v2 = applyInverseTo(Vector3D.plusJ);
if ((v2.getZ() < -0.9999999999) || (v2.getZ() > 0.9999999999)) {
throw new CardanEulerSingularityException(true);
}
return new double[] {
Math.atan2(v1.getX(), v1.getZ()),
-Math.asin(v2.getZ()),
Math.atan2(v2.getX(), v2.getY())
};
} else if (order == RotationOrder.YZX) {
// r (Vector3D.plusI) coordinates are :
// cos (psi) cos (theta), sin (psi), -cos (psi) sin (theta)
// (-r) (Vector3D.plusJ) coordinates are :
// sin (psi), cos (phi) cos (psi), -sin (phi) cos (psi)
// and we can choose to have psi in the interval [-PI/2 ; +PI/2]
Vector3D v1 = applyTo(Vector3D.plusI);
Vector3D v2 = applyInverseTo(Vector3D.plusJ);
if ((v2.getX() < -0.9999999999) || (v2.getX() > 0.9999999999)) {
throw new CardanEulerSingularityException(true);
}
return new double[] {
Math.atan2(-(v1.getZ()), v1.getX()),
Math.asin(v2.getX()),
Math.atan2(-(v2.getZ()), v2.getY())
};
} else if (order == RotationOrder.ZXY) {
// r (Vector3D.plusJ) coordinates are :
// -cos (phi) sin (psi), cos (phi) cos (psi), sin (phi)
// (-r) (Vector3D.plusK) coordinates are :
// -sin (theta) cos (phi), sin (phi), cos (theta) cos (phi)
// and we can choose to have phi in the interval [-PI/2 ; +PI/2]
Vector3D v1 = applyTo(Vector3D.plusJ);
Vector3D v2 = applyInverseTo(Vector3D.plusK);
if ((v2.getY() < -0.9999999999) || (v2.getY() > 0.9999999999)) {
throw new CardanEulerSingularityException(true);
}
return new double[] {
Math.atan2(-(v1.getX()), v1.getY()),
Math.asin(v2.getY()),
Math.atan2(-(v2.getX()), v2.getZ())
};
} else if (order == RotationOrder.ZYX) {
// r (Vector3D.plusI) coordinates are :
// cos (theta) cos (psi), cos (theta) sin (psi), -sin (theta)
// (-r) (Vector3D.plusK) coordinates are :
// -sin (theta), sin (phi) cos (theta), cos (phi) cos (theta)
// and we can choose to have theta in the interval [-PI/2 ; +PI/2]
Vector3D v1 = applyTo(Vector3D.plusI);
Vector3D v2 = applyInverseTo(Vector3D.plusK);
if ((v2.getX() < -0.9999999999) || (v2.getX() > 0.9999999999)) {
throw new CardanEulerSingularityException(true);
}
return new double[] {
Math.atan2(v1.getY(), v1.getX()),
-Math.asin(v2.getX()),
Math.atan2(v2.getY(), v2.getZ())
};
} else if (order == RotationOrder.XYX) {
// r (Vector3D.plusI) coordinates are :
// cos (theta), sin (phi1) sin (theta), -cos (phi1) sin (theta)
// (-r) (Vector3D.plusI) coordinates are :
// cos (theta), sin (theta) sin (phi2), sin (theta) cos (phi2)
// and we can choose to have theta in the interval [0 ; PI]
Vector3D v1 = applyTo(Vector3D.plusI);
Vector3D v2 = applyInverseTo(Vector3D.plusI);
if ((v2.getX() < -0.9999999999) || (v2.getX() > 0.9999999999)) {
throw new CardanEulerSingularityException(false);
}
return new double[] {
Math.atan2(v1.getY(), -v1.getZ()),
Math.acos(v2.getX()),
Math.atan2(v2.getY(), v2.getZ())
};
} else if (order == RotationOrder.XZX) {
// r (Vector3D.plusI) coordinates are :
// cos (psi), cos (phi1) sin (psi), sin (phi1) sin (psi)
// (-r) (Vector3D.plusI) coordinates are :
// cos (psi), -sin (psi) cos (phi2), sin (psi) sin (phi2)
// and we can choose to have psi in the interval [0 ; PI]
Vector3D v1 = applyTo(Vector3D.plusI);
Vector3D v2 = applyInverseTo(Vector3D.plusI);
if ((v2.getX() < -0.9999999999) || (v2.getX() > 0.9999999999)) {
throw new CardanEulerSingularityException(false);
}
return new double[] {
Math.atan2(v1.getZ(), v1.getY()),
Math.acos(v2.getX()),
Math.atan2(v2.getZ(), -v2.getY())
};
} else if (order == RotationOrder.YXY) {
// r (Vector3D.plusJ) coordinates are :
// sin (theta1) sin (phi), cos (phi), cos (theta1) sin (phi)
// (-r) (Vector3D.plusJ) coordinates are :
// sin (phi) sin (theta2), cos (phi), -sin (phi) cos (theta2)
// and we can choose to have phi in the interval [0 ; PI]
Vector3D v1 = applyTo(Vector3D.plusJ);
Vector3D v2 = applyInverseTo(Vector3D.plusJ);
if ((v2.getY() < -0.9999999999) || (v2.getY() > 0.9999999999)) {
throw new CardanEulerSingularityException(false);
}
return new double[] {
Math.atan2(v1.getX(), v1.getZ()),
Math.acos(v2.getY()),
Math.atan2(v2.getX(), -v2.getZ())
};
} else if (order == RotationOrder.YZY) {
// r (Vector3D.plusJ) coordinates are :
// -cos (theta1) sin (psi), cos (psi), sin (theta1) sin (psi)
// (-r) (Vector3D.plusJ) coordinates are :
// sin (psi) cos (theta2), cos (psi), sin (psi) sin (theta2)
// and we can choose to have psi in the interval [0 ; PI]
Vector3D v1 = applyTo(Vector3D.plusJ);
Vector3D v2 = applyInverseTo(Vector3D.plusJ);
if ((v2.getY() < -0.9999999999) || (v2.getY() > 0.9999999999)) {
throw new CardanEulerSingularityException(false);
}
return new double[] {
Math.atan2(v1.getZ(), -v1.getX()),
Math.acos(v2.getY()),
Math.atan2(v2.getZ(), v2.getX())
};
} else if (order == RotationOrder.ZXZ) {
// r (Vector3D.plusK) coordinates are :
// sin (psi1) sin (phi), -cos (psi1) sin (phi), cos (phi)
// (-r) (Vector3D.plusK) coordinates are :
// sin (phi) sin (psi2), sin (phi) cos (psi2), cos (phi)
// and we can choose to have phi in the interval [0 ; PI]
Vector3D v1 = applyTo(Vector3D.plusK);
Vector3D v2 = applyInverseTo(Vector3D.plusK);
if ((v2.getZ() < -0.9999999999) || (v2.getZ() > 0.9999999999)) {
throw new CardanEulerSingularityException(false);
}
return new double[] {
Math.atan2(v1.getX(), -v1.getY()),
Math.acos(v2.getZ()),
Math.atan2(v2.getX(), v2.getY())
};
} else { // last possibility is ZYZ
// r (Vector3D.plusK) coordinates are :
// cos (psi1) sin (theta), sin (psi1) sin (theta), cos (theta)
// (-r) (Vector3D.plusK) coordinates are :
// -sin (theta) cos (psi2), sin (theta) sin (psi2), cos (theta)
// and we can choose to have theta in the interval [0 ; PI]
Vector3D v1 = applyTo(Vector3D.plusK);
Vector3D v2 = applyInverseTo(Vector3D.plusK);
if ((v2.getZ() < -0.9999999999) || (v2.getZ() > 0.9999999999)) {
throw new CardanEulerSingularityException(false);
}
return new double[] {
Math.atan2(v1.getY(), v1.getX()),
Math.acos(v2.getZ()),
Math.atan2(v2.getY(), -v2.getX())
};
}
}
/** Get the 3X3 matrix corresponding to the instance
* @return the matrix corresponding to the instance
*/
public double[][] getMatrix() {
// products
double q0q0 = q0 * q0;
double q0q1 = q0 * q1;
double q0q2 = q0 * q2;
double q0q3 = q0 * q3;
double q1q1 = q1 * q1;
double q1q2 = q1 * q2;
double q1q3 = q1 * q3;
double q2q2 = q2 * q2;
double q2q3 = q2 * q3;
double q3q3 = q3 * q3;
// create the matrix
double[][] m = new double[3][];
m[0] = new double[3];
m[1] = new double[3];
m[2] = new double[3];
m [0][0] = 2.0 * (q0q0 + q1q1) - 1.0;
m [1][0] = 2.0 * (q1q2 - q0q3);
m [2][0] = 2.0 * (q1q3 + q0q2);
m [0][1] = 2.0 * (q1q2 + q0q3);
m [1][1] = 2.0 * (q0q0 + q2q2) - 1.0;
m [2][1] = 2.0 * (q2q3 - q0q1);
m [0][2] = 2.0 * (q1q3 - q0q2);
m [1][2] = 2.0 * (q2q3 + q0q1);
m [2][2] = 2.0 * (q0q0 + q3q3) - 1.0;
return m;
}
/** Apply the rotation to a vector.
* @param u vector to apply the rotation to
* @return a new vector which is the image of u by the rotation
*/
public Vector3D applyTo(Vector3D u) {
double x = u.getX();
double y = u.getY();
double z = u.getZ();
double s = q1 * x + q2 * y + q3 * z;
return new Vector3D(2 * (q0 * (x * q0 - (q2 * z - q3 * y)) + s * q1) - x,
2 * (q0 * (y * q0 - (q3 * x - q1 * z)) + s * q2) - y,
2 * (q0 * (z * q0 - (q1 * y - q2 * x)) + s * q3) - z);
}
/** Apply the inverse of the rotation to a vector.
* @param u vector to apply the inverse of the rotation to
* @return a new vector which such that u is its image by the rotation
*/
public Vector3D applyInverseTo(Vector3D u) {
double x = u.getX();
double y = u.getY();
double z = u.getZ();
double s = q1 * x + q2 * y + q3 * z;
double m0 = -q0;
return new Vector3D(2 * (m0 * (x * m0 - (q2 * z - q3 * y)) + s * q1) - x,
2 * (m0 * (y * m0 - (q3 * x - q1 * z)) + s * q2) - y,
2 * (m0 * (z * m0 - (q1 * y - q2 * x)) + s * q3) - z);
}
/** Apply the instance to another rotation.
* Applying the instance to a rotation is computing the composition
* in an order compliant with the following rule : let u be any
* vector and v its image by r (i.e. r.applyTo(u) = v), let w be the image
* of v by the instance (i.e. applyTo(v) = w), then w = comp.applyTo(u),
* where comp = applyTo(r).
* @param r rotation to apply the rotation to
* @return a new rotation which is the composition of r by the instance
*/
public Rotation applyTo(Rotation r) {
return new Rotation(r.q0 * q0 - (r.q1 * q1 + r.q2 * q2 + r.q3 * q3),
r.q1 * q0 + r.q0 * q1 + (r.q2 * q3 - r.q3 * q2),
r.q2 * q0 + r.q0 * q2 + (r.q3 * q1 - r.q1 * q3),
r.q3 * q0 + r.q0 * q3 + (r.q1 * q2 - r.q2 * q1),
false);
}
/** Apply the inverse of the instance to another rotation.
* Applying the inverse of the instance to a rotation is computing
* the composition in an order compliant with the following rule :
* let u be any vector and v its image by r (i.e. r.applyTo(u) = v),
* let w be the inverse image of v by the instance
* (i.e. applyInverseTo(v) = w), then w = comp.applyTo(u), where
* comp = applyInverseTo(r).
* @param r rotation to apply the rotation to
* @return a new rotation which is the composition of r by the inverse
* of the instance
*/
public Rotation applyInverseTo(Rotation r) {
return new Rotation(-r.q0 * q0 - (r.q1 * q1 + r.q2 * q2 + r.q3 * q3),
-r.q1 * q0 + r.q0 * q1 + (r.q2 * q3 - r.q3 * q2),
-r.q2 * q0 + r.q0 * q2 + (r.q3 * q1 - r.q1 * q3),
-r.q3 * q0 + r.q0 * q3 + (r.q1 * q2 - r.q2 * q1),
false);
}
/** Perfect orthogonality on a 3X3 matrix.
* @param m initial matrix (not exactly orthogonal)
* @param threshold convergence threshold for the iterative
* orthogonality correction (convergence is reached when the
* difference between two steps of the Frobenius norm of the
* correction is below this threshold)
* @return an orthogonal matrix close to m
* @exception NotARotationMatrixException if the matrix cannot be
* orthogonalized with the given threshold after 10 iterations
*/
private double[][] orthogonalizeMatrix(double[][] m, double threshold)
throws NotARotationMatrixException {
double[] m0 = m[0];
double[] m1 = m[1];
double[] m2 = m[2];
double x00 = m0[0];
double x01 = m0[1];
double x02 = m0[2];
double x10 = m1[0];
double x11 = m1[1];
double x12 = m1[2];
double x20 = m2[0];
double x21 = m2[1];
double x22 = m2[2];
double fn = 0;
double fn1;
double[][] o = new double[3][3];
double[] o0 = o[0];
double[] o1 = o[1];
double[] o2 = o[2];
// iterative correction: Xn+1 = Xn - 0.5 * (Xn.Mt.Xn - M)
int i = 0;
while (++i < 11) {
// Mt.Xn
double mx00 = m0[0] * x00 + m1[0] * x10 + m2[0] * x20;
double mx10 = m0[1] * x00 + m1[1] * x10 + m2[1] * x20;
double mx20 = m0[2] * x00 + m1[2] * x10 + m2[2] * x20;
double mx01 = m0[0] * x01 + m1[0] * x11 + m2[0] * x21;
double mx11 = m0[1] * x01 + m1[1] * x11 + m2[1] * x21;
double mx21 = m0[2] * x01 + m1[2] * x11 + m2[2] * x21;
double mx02 = m0[0] * x02 + m1[0] * x12 + m2[0] * x22;
double mx12 = m0[1] * x02 + m1[1] * x12 + m2[1] * x22;
double mx22 = m0[2] * x02 + m1[2] * x12 + m2[2] * x22;
// Xn+1
o0[0] = x00 - 0.5 * (x00 * mx00 + x01 * mx10 + x02 * mx20 - m0[0]);
o0[1] = x01 - 0.5 * (x00 * mx01 + x01 * mx11 + x02 * mx21 - m0[1]);
o0[2] = x02 - 0.5 * (x00 * mx02 + x01 * mx12 + x02 * mx22 - m0[2]);
o1[0] = x10 - 0.5 * (x10 * mx00 + x11 * mx10 + x12 * mx20 - m1[0]);
o1[1] = x11 - 0.5 * (x10 * mx01 + x11 * mx11 + x12 * mx21 - m1[1]);
o1[2] = x12 - 0.5 * (x10 * mx02 + x11 * mx12 + x12 * mx22 - m1[2]);
o2[0] = x20 - 0.5 * (x20 * mx00 + x21 * mx10 + x22 * mx20 - m2[0]);
o2[1] = x21 - 0.5 * (x20 * mx01 + x21 * mx11 + x22 * mx21 - m2[1]);
o2[2] = x22 - 0.5 * (x20 * mx02 + x21 * mx12 + x22 * mx22 - m2[2]);
// correction on each elements
double corr00 = o0[0] - m0[0];
double corr01 = o0[1] - m0[1];
double corr02 = o0[2] - m0[2];
double corr10 = o1[0] - m1[0];
double corr11 = o1[1] - m1[1];
double corr12 = o1[2] - m1[2];
double corr20 = o2[0] - m2[0];
double corr21 = o2[1] - m2[1];
double corr22 = o2[2] - m2[2];
// Frobenius norm of the correction
fn1 = corr00 * corr00 + corr01 * corr01 + corr02 * corr02 +
corr10 * corr10 + corr11 * corr11 + corr12 * corr12 +
corr20 * corr20 + corr21 * corr21 + corr22 * corr22;
// convergence test
if (Math.abs(fn1 - fn) <= threshold)
return o;
// prepare next iteration
x00 = o0[0];
x01 = o0[1];
x02 = o0[2];
x10 = o1[0];
x11 = o1[1];
x12 = o1[2];
x20 = o2[0];
x21 = o2[1];
x22 = o2[2];
fn = fn1;
}
// the algorithm did not converge after 10 iterations
throw new NotARotationMatrixException("unable to orthogonalize matrix" +
" in {0} iterations",
new Object[] {
Integer.toString(i - 1)
});
}
/** Scalar coordinate of the quaternion. */
private final double q0;
/** First coordinate of the vectorial part of the quaternion. */
private final double q1;
/** Second coordinate of the vectorial part of the quaternion. */
private final double q2;
/** Third coordinate of the vectorial part of the quaternion. */
private final double q3;
/** Serializable version identifier */
private static final long serialVersionUID = 8225864499430109352L;
}
The table below shows all metrics for Rotation.java.
| Metric | Value | Description | |
|---|---|---|---|
| BLOCKS | 67.00 | Number of blocks | |
| BLOCK_COMMENT | 16.00 | Number of block comment lines | |
| COMMENTS | 403.00 | Comment lines | |
| COMMENT_DENSITY | 0.86 | Comment density | |
| COMPARISONS | 119.00 | Number of comparison operators | |
| CYCLOMATIC | 78.00 | Cyclomatic complexity | |
| DECL_COMMENTS | 28.00 | Comments in declarations | |
| DOC_COMMENT | 279.00 | Number of javadoc comment lines | |
| ELOC | 467.00 | Effective lines of code | |
| EXEC_COMMENTS | 43.00 | Comments in executable code | |
| EXITS | 23.00 | Procedure exits | |
| FUNCTIONS | 21.00 | Number of function declarations | |
| HALSTEAD_DIFFICULTY | 163.57 | Halstead difficulty | |
| HALSTEAD_EFFORT | 0.00 | Halstead effort | |
| INTERFACE_COMPLEXITY | 82.00 | Interface complexity | |
| JAVA0001 | 0.00 | JAVA0001 Package name does not contain only lower case letters | |
| JAVA0002 | 0.00 | JAVA0002 Package name does not begin with a top level domain name or country code | |
| JAVA0003 | 0.00 | JAVA0003 Minimize use of on-demand (.*) imports | |
| JAVA0004 | 0.00 | JAVA0004 Unnecessary import from java.lang | |
| JAVA0005 | 0.00 | JAVA0005 Imports not in specified order | |
| JAVA0006 | 0.00 | JAVA0006 Empty finally block | |
| JAVA0007 | 0.00 | JAVA0007 Should not declare public field | |
| JAVA0008 | 0.00 | JAVA0008 Empty catch block | |
| JAVA0009 | 0.00 | JAVA0009 Protected member in final class | |
| JAVA0010 | 0.00 | JAVA0010 Non-instantiable class does not contain a non-private static member | |
| JAVA0011 | 0.00 | JAVA0011 Abstract class does not contain an abstract method | |
| JAVA0012 | 0.00 | JAVA0012 Non-constructor method with same name as declaring class | |
| JAVA0013 | 0.00 | JAVA0013 Non-blank final field is not static | |
| JAVA0014 | 0.00 | JAVA0014 Class with only static members has non-private constructor | |
| JAVA0015 | 0.00 | JAVA0015 Package class contains public nested type | |
| JAVA0016 | 0.00 | JAVA0016 Abstract class contains public constructor | |
| JAVA0017 | 0.00 | JAVA0017 Class name does not have required form | |
| JAVA0018 | 0.00 | JAVA0018 Method name does not have required form | |
| JAVA0019 | 0.00 | JAVA0019 Interface name does not have required form | |
| JAVA0020 | 0.00 | JAVA0020 Field name does not have required form | |
| JAVA0021 | 0.00 | JAVA0021 Interface method name does not have required form | |
| JAVA0022 | 0.00 | JAVA0022 Static final field name does not have required form | |
| JAVA0023 | 0.00 | JAVA0023 Empty finalize method | |
| JAVA0024 | 0.00 | JAVA0024 Empty class | |
| JAVA0025 | 0.00 | JAVA0025 Method override is empty | |
| JAVA0026 | 0.00 | JAVA0026 Finalize method with parameters | |
| JAVA0029 | 0.00 | JAVA0029 Private method not used | |
| JAVA0030 | 0.00 | JAVA0030 Private field not used | |
| JAVA0031 | 0.00 | JAVA0031 Case statement not properly closed | |
| JAVA0032 | 0.00 | JAVA0032 Switch statement missing default | |
| JAVA0033 | 0.00 | JAVA0033 default: not last case in switch statement | |
| JAVA0034 | 1.00 | JAVA0034 Missing braces in if statement | |
| JAVA0035 | 0.00 | JAVA0035 Missing braces in for statement | |
| JAVA0036 | 0.00 | JAVA0036 Missing braces in while statement | |
| JAVA0038 | 0.00 | JAVA0038 Non-case label in switch statement | |
| JAVA0039 | 0.00 | JAVA0039 Break statement with label | |
| JAVA0040 | 0.00 | JAVA0040 Switch statement contains N cases (maximum: M) | |
| JAVA0041 | 0.00 | JAVA0041 Nested synchronized block | |
| JAVA0042 | 0.00 | JAVA0042 Empty synchronized statement | |
| JAVA0043 | 0.00 | JAVA0043 Inner class does not use outer class | |
| JAVA0044 | 0.00 | JAVA0044 Serializable class with no instance variables | |
| JAVA0045 | 0.00 | JAVA0045 Serializable class with only transient fields | |
| JAVA0046 | 0.00 | JAVA0046 Name of class not derived from Exception ends with 'Exception' | |
| JAVA0047 | 0.00 | JAVA0047 Serializable class derives from invalid base class | |
| JAVA0048 | 0.00 | JAVA0048 Name of class derived from Exception does not end with 'Exception' | |
| JAVA0049 | 0.00 | JAVA0049 Nested block at depth N (maximum: M) | |
| JAVA0050 | 0.00 | JAVA0050 Class derives from java.lang.Error | |
| JAVA0051 | 0.00 | JAVA0051 Class derives from java.lang.RuntimeException | |
| JAVA0052 | 0.00 | JAVA0052 Class derives from java.lang.Throwable | |
| JAVA0053 | 0.00 | JAVA0053 Unused label | |
| JAVA0054 | 0.00 | JAVA0054 Inheritance depth N exceeds maximum M | |
| JAVA0055 | 0.00 | JAVA0055 Class should be interface | |
| JAVA0056 | 0.00 | JAVA0056 Unnecessary abstract modifier for interface or annotation | |
| JAVA0057 | 0.00 | JAVA0057 Unnecessary default constructor | |
| JAVA0058 | 0.00 | JAVA0058 Constructor calls super() | |
| JAVA0059 | 0.00 | JAVA0059 Method override only calls super() | |
| JAVA0061 | 0.00 | JAVA0061 Inaccessible member in anonymous class | |
| JAVA0062 | 0.00 | JAVA0062 Public class missing public member or protected constructor | |
| JAVA0063 | 0.00 | JAVA0063 Identifier name should not contain '$' | |
| JAVA0064 | 0.00 | JAVA0064 N variations of identifier name (maximum: M) | |
| JAVA0065 | 0.00 | JAVA0065 Unnecessary final modifier for method in final class | |
| JAVA0066 | 0.00 | JAVA0066 Unnecessary modifier for interface nested type | |
| JAVA0067 | 0.00 | JAVA0067 Array descriptor on identifier name | |
| JAVA0068 | 0.00 | JAVA0068 Modifiers not declared in recommended order | |
| JAVA0071 | 0.00 | JAVA0071 Strings compared with == | |
| JAVA0073 | 0.00 | JAVA0073 Integer division in floating-point context | |
| JAVA0074 | 0.00 | JAVA0074 Use of Object.notify() | |
| JAVA0075 | 0.00 | JAVA0075 Method parameter hides field | |
| JAVA0076 | 48.00 | JAVA0076 Use of magic number | |
| JAVA0077 | 0.00 | JAVA0077 Private field not used in declaring class | |
| JAVA0078 | 10.00 | JAVA0078 Floating point values compared with == | |
| JAVA0079 | 0.00 | JAVA0079 Use of instance to reference static member | |
| JAVA0080 | 0.00 | JAVA0080 Import declaration not used | |
| JAVA0081 | 0.00 | JAVA0081 Boolean literal in comparison | |
| JAVA0082 | 0.00 | JAVA0082 Unnecessary widening cast | |
| JAVA0083 | 0.00 | JAVA0083 Unnecessary instanceof test | |
| JAVA0084 | 0.00 | JAVA0084 Should use compound assignment operator | |
| JAVA0085 | 0.00 | JAVA0085 Use of sun.* class | |
| JAVA0087 | 0.00 | JAVA0087 Use of Thread.sleep() | |
| JAVA0089 | 0.00 | JAVA0089 Use of restricted package | |
| JAVA0092 | 0.00 | JAVA0092 Use of restricted type | |
| JAVA0093 | 0.00 | JAVA0093 Redundant assignment | |
| JAVA0094 | 0.00 | JAVA0094 Field hides a superclass field | |
| JAVA0095 | 0.00 | JAVA0095 Uninitialized private field | |
| JAVA0096 | 0.00 | JAVA0096 Field in nested class hides outer field | |
| JAVA0098 | 0.00 | JAVA0098 Minimize use of implicit field initializers | |
| JAVA0100 | 0.00 | JAVA0100 Class contains N non-final fields (maximum: M) | |
| JAVA0101 | 0.00 | JAVA0101 Unnecessary modifier for field in interface | |
| JAVA0102 | 0.00 | JAVA0102 Last statement in finalize() not super.finalize() | |
| JAVA0103 | 0.00 | JAVA0103 Explicit call to finalize() | |
| JAVA0104 | 0.00 | JAVA0104 finalize() only calls super.finalize() | |
| JAVA0105 | 0.00 | JAVA0105 Duplicate import declaration | |
| JAVA0106 | 0.00 | JAVA0106 Unnecessary import from current package | |
| JAVA0108 | 0.00 | JAVA0108 Incorrect javadoc: no @param tag for 'parameter' | |
| JAVA0109 | 0.00 | JAVA0109 Incorrect javadoc: no parameter 'parameter' | |
| JAVA0110 | 0.00 | JAVA0110 Incorrect javadoc: no @return tag | |
| JAVA0111 | 0.00 | JAVA0111 Incorrect javadoc: @return tag for void method | |
| JAVA0112 | 0.00 | JAVA0112 Incorrect javadoc: no exception 'exception' in throws | |
| JAVA0113 | 1.00 | JAVA0113 Incorrect javadoc: no @author tag | |
| JAVA0114 | 0.00 | JAVA0114 Incorrect javadoc: no @version tag | |
| JAVA0115 | 0.00 | JAVA0115 Incorrect javadoc: no @throws or @exception tag for 'exception' | |
| JAVA0116 | 0.00 | JAVA0116 Missing javadoc: field 'field' | |
| JAVA0117 | 0.00 | JAVA0117 Missing javadoc: method 'method' | |
| JAVA0118 | 0.00 | JAVA0118 Missing javadoc: type 'type' | |
| JAVA0119 | 0.00 | JAVA0119 Control variable changed within body of for loop | |
| JAVA0123 | 0.00 | JAVA0123 Use all three components of for loop | |
| JAVA0125 | 0.00 | JAVA0125 Continue statement with label | |
| JAVA0126 | 0.00 | JAVA0126 Method declares unchecked exception in throws | |
| JAVA0128 | 0.00 | JAVA0128 Public constructor in non-public class | |
| JAVA0130 | 1.00 | JAVA0130 Non-static method does not use instance fields | |
| JAVA0131 | 0.00 | JAVA0131 Compatible method does not override base | |
| JAVA0132 | 0.00 | JAVA0132 Method overload with compatible signature | |
| JAVA0133 | 0.00 | JAVA0133 Non-synchronized method overrides synchronized method | |
| JAVA0135 | 0.00 | JAVA0135 Only one of Object.equals and Object.hashCode defined: missing 'method' | |
| JAVA0136 | 1.00 | JAVA0136 N methods defined in class (maximum: M) | |
| JAVA0137 | 0.00 | JAVA0137 Non-abstract class missing constructor | |
| JAVA0138 | 0.00 | JAVA0138 N parameters defined for method (maximum: M) | |
| JAVA0139 | 0.00 | JAVA0139 Definition of main other than public static void main(java.lang.String[]) | |
| JAVA0141 | 0.00 | JAVA0141 Unnecessary modifier for method in interface | |
| JAVA0143 | 0.00 | JAVA0143 Synchronized method | |
| JAVA0144 | 0.00 | JAVA0144 Line exceeds maximum M characters | |
| JAVA0145 | 0.00 | JAVA0145 Tab character used in source file | |
| JAVA0150 | 0.00 | JAVA0150 java.lang.Error (or subclass) thrown | |
| JAVA0153 | 0.00 | JAVA0153 Inefficient conversion of integer to string | |
| JAVA0159 | 0.00 | JAVA0159 Inefficient conversion of string to integer | |
| JAVA0160 | 0.00 | JAVA0160 Method does not throw specified exception | |
| JAVA0161 | 0.00 | JAVA0161 Conditional wait() not in loop | |
| JAVA0163 | 0.00 | JAVA0163 Empty statement | |
| JAVA0165 | 0.00 | JAVA0165 Conflicting return statement in finally block | |
| JAVA0166 | 0.00 | JAVA0166 Generic exception caught | |
| JAVA0167 | 0.00 | JAVA0167 ThreadDeath not rethrown | |
| JAVA0169 | 0.00 | JAVA0169 Unnecessary catch block: exception 'exception' | |
| JAVA0170 | 0.00 | JAVA0170 Caught exception not derived from java.lang.Exception | |
| JAVA0171 | 0.00 | JAVA0171 Unused local variable | |
| JAVA0173 | 0.00 | JAVA0173 Unused method parameter | |
| JAVA0174 | 0.00 | JAVA0174 Assigned local variable never used | |
| JAVA0175 | 0.00 | JAVA0175 Successive assignment to variable | |
| JAVA0176 | 0.00 | JAVA0176 Local variable name does not have required form | |
| JAVA0177 | 1.00 | JAVA0177 Variable declaration missing initializer | |
| JAVA0179 | 0.00 | JAVA0179 Local variable hides visible field | |
| JAVA0233 | 0.00 | JAVA0233 Definition of serialVersionUID other than 'private static final long serialVersionUID' | |
| JAVA0234 | 0.00 | JAVA0234 Class is Serializable but does not define serialVersionUID | |
| JAVA0235 | 0.00 | JAVA0235 Class defines serialVersionUID but does not implement Serializable | |
| JAVA0236 | 0.00 | JAVA0236 Attempt to clone an object which does not implement Cloneable | |
| JAVA0237 | 0.00 | JAVA0237 Class implements Cloneable but does not have public clone method | |
| JAVA0238 | 0.00 | JAVA0238 Clone method does not call super.clone() | |
| JAVA0239 | 0.00 | JAVA0239 Class declares 'readObject' or 'writeObject' but does not implement Serializable | |
| JAVA0240 | 0.00 | JAVA0240 Serializable class which declares readObject or writeObject but not both | |
| JAVA0241 | 0.00 | JAVA0241 'readObject' or 'writeObject' should be declared private in Serializable class | |
| JAVA0242 | 0.00 | JAVA0242 Transient field in non-Serializable class | |
| JAVA0243 | 0.00 | JAVA0243 'readResolve' or 'writeReplace' should be declared private or protected | |
| JAVA0244 | 0.00 | JAVA0244 Field or method name in subclass differs only by case from inherited field or method | |
| JAVA0245 | 0.00 | JAVA0245 JUnit TestCase with non-trivial constructor | |
| JAVA0246 | 0.00 | JAVA0246 JUnit assertXXX statement missing message parameter | |
| JAVA0247 | 0.00 | JAVA0247 JUnit 'setUp()' and 'tearDown()' should call super method | |
| JAVA0248 | 0.00 | JAVA0248 JUnit method 'setUp' or 'tearDown' with incorrect signature | |
| JAVA0249 | 0.00 | JAVA0249 JUnit TestCase 'suite()' should be declared static | |
| JAVA0250 | 0.00 | JAVA0250 JUnit TestCase declares testXXX method with incorrect signature | |
| JAVA0251 | 0.00 | JAVA0251 Use '%n' for line breaks in printf/format for platform independence | |
| JAVA0252 | 0.00 | JAVA0252 'enum' is a Java 1.5 reserved word | |
| JAVA0253 | 0.00 | JAVA0253 Not all enum constants consumed in switch statement | |
| JAVA0254 | 0.00 | JAVA0254 Use enhanced for loop construct instead of Iterator | |
| JAVA0255 | 0.00 | JAVA0255 Result of method invocation not used | |
| JAVA0256 | 0.00 | JAVA0256 Assignment of external collection/array to field | |
| JAVA0257 | 0.00 | JAVA0257 Use of 'Constant Interface' anti-pattern | |
| JAVA0258 | 0.00 | JAVA0258 Implement Iterable for foreach compatibility | |
| JAVA0259 | 0.00 | JAVA0259 Return of collection/array field | |
| JAVA0260 | 0.00 | JAVA0260 Use 'enum' instead of Enumerated Type pattern | |
| JAVA0261 | 0.00 | JAVA0261 Use specialized Enum collection types | |
| JAVA0262 | 0.00 | JAVA0262 Use of char in integer context | |
| JAVA0263 | 0.00 | JAVA0263 Long literal ends with 'l' instead of 'L' | |
| JAVA0264 | 0.00 | JAVA0264 Integer math in long context - check for overflow | |
| JAVA0265 | 0.00 | JAVA0265 Use of Throwable.printStackTrace() | |
| JAVA0266 | 0.00 | JAVA0266 Use of System.out | |
| JAVA0267 | 0.00 | JAVA0267 Use of System.err | |
| JAVA0269 | 0.00 | JAVA0269 Contents of StringBuffer never used | |
| JAVA0270 | 0.00 | JAVA0270 Use Java 5.0 enhanced for loop construct to iterate over all elements in an array | |
| JAVA0271 | 0.00 | JAVA0271 Minimize use of on-demand (.*) static imports | |
| JAVA0272 | 0.00 | JAVA0272 Thread.run() called | |
| JAVA0273 | 0.00 | JAVA0273 Non-final derivative of Thread calls start() in constructor | |
| JAVA0274 | 0.00 | JAVA0274 Serializable class has a synchronized readObject() | |
| JAVA0275 | 0.00 | JAVA0275 Serializable class has a synchronized writeObject() and no other synchronized methods | |
| JAVA0276 | 0.00 | JAVA0276 Unnecessary use of String constructor | |
| JAVA0277 | 0.00 | JAVA0277 Iterator.next() implementation does not throw NoSuchElementException | |
| JAVA0278 | 0.00 | JAVA0278 Unnecessary use of Boolean constructor | |
| JAVA0279 | 0.00 | JAVA0279 Serialization method readObject or readObjectNoData calls an overridable method | |
| JAVA0280 | 0.00 | JAVA0280 IllegalMonitorStateException caught | |
| JAVA0281 | 0.00 | JAVA0281 Iterator.next() not called in loop | |
| JAVA0282 | 0.00 | JAVA0282 Call to Iterator.next() in loop which does not test Iterator.hasNext() | |
| JAVA0283 | 0.00 | JAVA0283 Control variable not updated in loop body | |
| JAVA0284 | 0.00 | JAVA0284 Explicit garbage collection | |
| JAVA0285 | 0.00 | JAVA0285 Dereference of potentially null variable | |
| JAVA0286 | 0.00 | JAVA0286 Dereference of null variable | |
| JAVA0287 | 0.00 | JAVA0287 Unnecessary null check | |
| JAVA0288 | 0.00 | JAVA0288 Inconsistent null check | |
| LINES | 1035.00 | Number of lines in the source file | |
| LINE_COMMENT | 108.00 | Number of line comments | |
| LOC | 518.00 | Lines of code | |
| LOGICAL_LINES | 301.00 | Number of statements | |
| LOOPS | 1.00 | Number of loops | |
| NEST_DEPTH | 4.00 | Maximum nesting depth | |
| OPERANDS | 2052.00 | Number of operands | |
| OPERATORS | 3632.00 | Number of operators | |
| PARAMS | 26.00 | Number of formal parameter declarations | |
| PROGRAM_LENGTH | 5684.00 | Halstead program length | |
| PROGRAM_VOCAB | 320.00 | Halstead program vocabulary | |
| PROGRAM_VOLUME | 0.00 | Halstead program volume | |
| RETURNS | 56.00 | Number of return points from functions | |
| SIZE | 40916.00 | Size of the file in bytes | |
| UNIQUE_OPERANDS | 276.00 | Number of unique operands | |
| UNIQUE_OPERATORS | 44.00 | Number of unique operators | |
| WHITESPACE | 114.00 | Number of whitespace lines | |