RadiiOfCurvature.java
/*
* Copyright (C) 2019 Alberto Irurueta Carro (alberto@irurueta.com)
*
* Licensed 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 com.irurueta.navigation.inertial;
import com.irurueta.units.Distance;
import com.irurueta.units.DistanceConverter;
import com.irurueta.units.DistanceUnit;
import java.io.Serial;
import java.io.Serializable;
import java.util.Objects;
/**
* Contains radii of curvature of the WGS84 ellipsoid at a given latitude.
*/
public class RadiiOfCurvature implements Serializable, Cloneable {
/**
* Serialization version. This is used to ensure compatibility of deserialization of permanently stored serialized
* instances.
*/
@Serial
private static final long serialVersionUID = 0L;
/**
* Meridian radius of curvature expressed in meters (m).
* This is the radius of curvature for north-south motion.
* It is the radius of curvature of a meridian, a cross-section of the ellipsoid
* surface in the north-down plane, at the point of interest (a given latitude).
* This is the same as the radius of the best-fitting circle to the meridian
* ellipse at the point of interest.
* The meridian radius of curvature varies with latitude and is smallest at the
* equator, where the geocentric radius is largest, and largest at the poles.
*/
private double rn;
/**
* Transverse radius of curvature expressed in meters (m).
* This is the radius of curvature for east-west motion.
* This is also known as the normal radius of curvature or prime vertical radius
* of curvature.
* It is the radius of curvature of a cross-section of the ellipsoid surface in
* the east-down plane at the point of interest.
* This is the vertical plane perpendicular to the meridian plane and is not
* the plane of constant latitude.
* The transverse radius of curvature varies with latitude and is smallest at the
* equator. It is also equal to the length of the normal from a point on the
* surface to the polar axis.
*/
private double re;
/**
* Constructor.
*/
public RadiiOfCurvature() {
}
/**
* Constructor.
*
* @param rn meridian radius of curvature expressed in meters (m).
* @param re transverse radius of curvature expressed in meters (m).
*/
public RadiiOfCurvature(final double rn, final double re) {
setValues(rn, re);
}
/**
* Constructor.
*
* @param rnDistance meridian radius of curvature.
* @param reDistance transverse radius of curvature.
*/
public RadiiOfCurvature(final Distance rnDistance, final Distance reDistance) {
setValues(rnDistance, reDistance);
}
/**
* Constructor.
*
* @param input instance to copy data from.
*/
public RadiiOfCurvature(final RadiiOfCurvature input) {
copyFrom(input);
}
/**
* Gets meridian radius of curvature expressed in meters (m).
* This is the radius of curvature for north-south motion.
* It is the radius of curvature of a meridian, a cross-section of the ellipsoid
* surface in the north-down plane, at the point of interest (a given latitude).
* This is the same as the radius of the best-fitting circle to the meridian
* ellipse at the point of interest.
* The meridian radius of curvature varies with latitude and is smallest at the
* equator, where the geocentric radius is largest, and largest at the poles.
*
* @return meridian radius of curvature expressed in meters (m).
*/
public double getRn() {
return rn;
}
/**
* Sets meridian radius of curvature expressed in meters (m).
* This is the radius of curvature for north-south motion.
* It is the radius of curvature of a meridian, a cross-section of the ellipsoid
* surface in the north-down plane, at the point of interest (a given latitude).
* This is the same as the radius of the best-fitting circle to the meridian
* ellipse at the point of interest.
* The meridian radius of curvature varies with latitude and is smallest at the
* equator, where the geocentric radius is largest, and largest at the poles.
*
* @param rn meridian radius of curvature expressed in meters (m).
*/
public void setRn(final double rn) {
this.rn = rn;
}
/**
* Gets transverse radius of curvature expressed in meters (m).
* This is the radius of curvature for east-wet motion.
* This is also known as the normal radius of curvature or prime vertical radius
* of curvature.
* It is the radius of curvature of a cross-section of the ellipsoid surface in
* the east-down plane at the point of interest.
* This is the vertical plane perpendicular to the meridian plane and is not
* the plane of constant latitude.
* The transverse radius of curvature varies with latitude and is smallest at the
* equator. It is also equal to the length of the normal from a point on the
* surface to the polar axis.
*
* @return transverse radius of curvature expressed in meters (m).
*/
public double getRe() {
return re;
}
/**
* Sets transverse radius of curvature expressed in meters (m).
* This is the radius of curvature for east-wet motion.
* This is also known as the normal radius of curvature or prime vertical radius
* of curvature.
* It is the radius of curvature of a cross-section of the ellipsoid surface in
* the east-down plane at the point of interest.
* This is the vertical plane perpendicular to the meridian plane and is not
* the plane of constant latitude.
* The transverse radius of curvature varies with latitude and is smallest at the
* equator. It is also equal to the length of the normal from a point on the
* surface to the polar axis.
*
* @param re transverse radius of curvature expressed in meters (m).
*/
public void setRe(final double re) {
this.re = re;
}
/**
* Sets radii of curvature.
*
* @param rn meridian radius of curvature expressed in meters (m).
* @param re transverse radius of curvature expressed in meters (m).
*/
public void setValues(final double rn, final double re) {
this.rn = rn;
this.re = re;
}
/**
* Gets meridian radius of curvature.
* This is the radius of curvature for north-south motion.
* It is the radius of curvature of a meridian, a cross-section of the ellipsoid
* surface in the north-down plane, at the point of interest (a given latitude).
* This is the same as the radius of the best-fitting circle to the meridian
* ellipse at the point of interest.
* The meridian radius of curvature varies with latitude and is smallest at the
* equator, where the geocentric radius is largest, and largest at the poles.
*
* @param result instance where meridian radius of curvature will be stored.
*/
public void getRnDistance(final Distance result) {
result.setValue(rn);
result.setUnit(DistanceUnit.METER);
}
/**
* Gets meridian radius of curvature.
* This is the radius of curvature for north-south motion.
* It is the radius of curvature of a meridian, a cross-section of the ellipsoid
* surface in the north-down plane, at the point of interest (a given latitude).
* This is the same as the radius of the best-fitting circle to the meridian
* ellipse at the point of interest.
* The meridian radius of curvature varies with latitude and is smallest at the
* equator, where the geocentric radius is largest, and largest at the poles.
*
* @return meridian radius of curvature.
*/
public Distance getRnDistance() {
return new Distance(rn, DistanceUnit.METER);
}
/**
* Sets meridian radius of curvature.
* This is the radius of curvature for north-south motion.
* It is the radius of curvature of a meridian, a cross-section of the ellipsoid
* surface in the north-down plane, at the point of interest (a given latitude).
* This is the same as the radius of the best-fitting circle to the meridian
* ellipse at the point of interest.
* The meridian radius of curvature varies with latitude and is smallest at the
* equator, where the geocentric radius is largest, and largest at the poles.
*
* @param rnDistance meridian radius of curvature to be set.
*/
public void setRnDistance(final Distance rnDistance) {
rn = DistanceConverter.convert(rnDistance.getValue().doubleValue(), rnDistance.getUnit(), DistanceUnit.METER);
}
/**
* Gets transverse radius or curvature.
* This is the radius of curvature for east-wet motion.
* This is also known as the normal radius of curvature or prime vertical radius
* of curvature.
* It is the radius of curvature of a cross-section of the ellipsoid surface in
* the east-down plane at the point of interest.
* This is the vertical plane perpendicular to the meridian plane and is not
* the plane of constant latitude.
* The transverse radius of curvature varies with latitude and is smallest at the
* equator. It is also equal to the length of the normal from a point on the
* surface to the polar axis.
*
* @param result instance where transverse radius of curvature will be stored.
*/
public void getReDistance(final Distance result) {
result.setValue(re);
result.setUnit(DistanceUnit.METER);
}
/**
* Gets transverse radius of curvature.
* This is the radius of curvature for east-wet motion.
* This is also known as the normal radius of curvature or prime vertical radius
* of curvature.
* It is the radius of curvature of a cross-section of the ellipsoid surface in
* the east-down plane at the point of interest.
* This is the vertical plane perpendicular to the meridian plane and is not
* the plane of constant latitude.
* The transverse radius of curvature varies with latitude and is smallest at the
* equator. It is also equal to the length of the normal from a point on the
* surface to the polar axis.
*
* @return transverse radius of curvature.
*/
public Distance getReDistance() {
return new Distance(re, DistanceUnit.METER);
}
/**
* Sets transverse radius of curvature.
* This is the radius of curvature for east-wet motion.
* This is also known as the normal radius of curvature or prime vertical radius
* of curvature.
* It is the radius of curvature of a cross-section of the ellipsoid surface in
* the east-down plane at the point of interest.
* This is the vertical plane perpendicular to the meridian plane and is not
* the plane of constant latitude.
* The transverse radius of curvature varies with latitude and is smallest at the
* equator. It is also equal to the length of the normal from a point on the
* surface to the polar axis.
*
* @param reDistance transverse radius of curvature to be set.
*/
public void setReDistance(final Distance reDistance) {
re = DistanceConverter.convert(reDistance.getValue().doubleValue(), reDistance.getUnit(), DistanceUnit.METER);
}
/**
* Sets radii of curvature.
*
* @param rnDistance meridian radius of curvature.
* @param reDistance transverse radius of curvature.
*/
public void setValues(final Distance rnDistance, final Distance reDistance) {
setRnDistance(rnDistance);
setReDistance(reDistance);
}
/**
* Copies this instance data into provided instance.
*
* @param output destination instance where data will be copied to.
*/
public void copyTo(final RadiiOfCurvature output) {
output.rn = rn;
output.re = re;
}
/**
* Copies data of provided instance into this instance.
*
* @param input instance to copy data from.
*/
public void copyFrom(final RadiiOfCurvature input) {
rn = input.rn;
re = input.re;
}
/**
* Computes and returns hash code for this instance. Hash codes are almost unique
* values that are useful for fast classification and storage of objects in collections.
*
* @return Hash code.
*/
@Override
public int hashCode() {
return Objects.hash(rn, re);
}
/**
* Checks if provided object is a RadiiOfCurvature instance having exactly the same
* contents as this instance.
*
* @param obj object to be compared.
* @return true if both objects are considered to be equal, false otherwise.
*/
@Override
public boolean equals(final Object obj) {
if (obj == null) {
return false;
}
if (obj == this) {
return true;
}
if (!(obj instanceof RadiiOfCurvature)) {
return false;
}
//noinspection PatternVariableCanBeUsed
final var other = (RadiiOfCurvature) obj;
return equals(other);
}
/**
* Checks if provided instance has exactly the same contents as this instance.
*
* @param other instance to be compared.
* @return true if both instances are considered to be equal, false otherwise.
*/
public boolean equals(final RadiiOfCurvature other) {
return equals(other, 0.0);
}
/**
* Checks if provided instance has contents similar to this instance up to provided
* threshold value.
*
* @param other instance to be compared.
* @param threshold maximum allowed difference between radii values.
* @return true if both instances are considered to be equal (up to provided
* threshold), false otherwise.
*/
public boolean equals(final RadiiOfCurvature other, final double threshold) {
if (other == null) {
return false;
}
return Math.abs(rn - other.rn) <= threshold && Math.abs(re - other.re) <= threshold;
}
/**
* Makes a copy of this instance.
*
* @return a copy of this instance.
* @throws CloneNotSupportedException if clone fails for some reason.
*/
@Override
protected Object clone() throws CloneNotSupportedException {
final var result = (RadiiOfCurvature) super.clone();
copyTo(result);
return result;
}
}