From: erik Date: Thu, 3 Aug 2006 18:45:23 +0000 (+0000) Subject: (no commit message) X-Git-Tag: BEFORE_MAVEN_MIGRATION~54 X-Git-Url: http://wamblee.org/gitweb/?a=commitdiff_plain;h=a4126765060aa3511147a8ca1cfd2985c188d8c0;p=utils --- diff --git a/gps/src/org/wamblee/gps/geometry/CoordinateSystem.java b/gps/src/org/wamblee/gps/geometry/CoordinateSystem.java new file mode 100644 index 00000000..9094336b --- /dev/null +++ b/gps/src/org/wamblee/gps/geometry/CoordinateSystem.java @@ -0,0 +1,31 @@ +/* + * Copyright 2006 the original author or authors. + * + * 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 org.wamblee.gps.geometry; + + +/** + * Represents a coordinate system. + */ +public interface CoordinateSystem { + + /** + * Conversion to a reference coordinate system. + * @param aCoordinates Coordinates. + * @return Coordinates in the reference system. + */ + Coordinates toReferenceSystem(Coordinates aCoordinates); +} diff --git a/gps/src/org/wamblee/gps/geometry/Coordinates.java b/gps/src/org/wamblee/gps/geometry/Coordinates.java new file mode 100644 index 00000000..544c92a1 --- /dev/null +++ b/gps/src/org/wamblee/gps/geometry/Coordinates.java @@ -0,0 +1,91 @@ +/* + * Copyright 2006 the original author or authors. + * + * 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 org.wamblee.gps.geometry; + +/** + * Coordinates in some 3-dimensional coordinate system. + */ +public class Coordinates { + + private double _x1; + private double _x2; + private double _x3; + + /** + * Constructs the coordinates. + * @param aX1 First coordinate. + * @param aX2 Second coordinate. + * @param aX3 Third coordinate. + */ + public Coordinates(double aX1, double aX2, double aX3) { + _x1 = aX1; + _x2 = aX2; + _x3 = aX3; + } + + public double getX1() { + return _x1; + } + + public double getX2() { + return _x2; + } + + public double getX3() { + return _x3; + } + + /* (non-Javadoc) + * @see java.lang.Object#toString() + */ + @Override + public String toString() { + return "(" + getX1() + ", " + getX2() + ", " + getX3() + ")"; + } + + public Coordinates add(Coordinates aC) { + return new Coordinates(_x1 + aC._x1, _x2 + aC._x2, _x3 + aC._x3); + } + + public Coordinates subtract(Coordinates aC) { + return new Coordinates(_x1 - aC._x1, _x2 - aC._x2, _x3 - aC._x3); + } + + public double innerProduct(Coordinates aC) { + return _x1 * aC._x1 + _x2 * aC._x2 + _x3 * aC._x3; + } + + public Coordinates outerProduct(Coordinates aC) { + return new Coordinates( + _x2*aC._x3 - _x3*aC._x2, + -_x1*aC._x3 + _x3*aC._x1, + _x1*aC._x2 - _x2*aC._x1 + ); + } + + public double norm() { + return Math.sqrt(innerProduct(this)); + } + + public Coordinates scale(double aMultiplier) { + return new Coordinates(_x1*aMultiplier, _x2*aMultiplier, _x3*aMultiplier); + } + + public Coordinates normalize() { + return scale(1.0/norm()); + } +} diff --git a/gps/src/org/wamblee/gps/geometry/Plane.java b/gps/src/org/wamblee/gps/geometry/Plane.java new file mode 100644 index 00000000..1be9b545 --- /dev/null +++ b/gps/src/org/wamblee/gps/geometry/Plane.java @@ -0,0 +1,73 @@ +/* + * Copyright 2006 the original author or authors. + * + * 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 org.wamblee.gps.geometry; + +import org.wamblee.general.Pair; + +/** + * Represents a plane. Usually used to represent a tangent plane to the earth surface to + * locally approximate the earth as flat. + */ +public class Plane { + + private static final double EPS = 1e-4; + + private Coordinates _point; + private Coordinates _normal; + private Coordinates _north; + private Coordinates _east; + + /** + * Constructs a plane. + * @param aPoint Point on the plane. + * @param aNormal Normal, not necessarily normalized. + */ + public Plane(Point aPoint, Point aNormal) { + _point = aPoint.getReferenceCoordinates(); + _normal = aNormal.getReferenceCoordinates().normalize(); + Coordinates north = new Coordinates(0.0, 0.0, 1.0); + _north = north.subtract(_normal.scale(north.innerProduct(_normal))).normalize(); + _east = _north.outerProduct(_normal); + + if ( _normal.innerProduct(_north) > EPS ) { + throw new IllegalArgumentException("North access is not within the plane"); + } + } + + /** + * Projects a point onto the plane. + * @param aPoint Point to project. + * @return Projected point. + */ + private Coordinates project(Point aPoint) { + Coordinates ref = aPoint.getReferenceCoordinates(); + double lambda = _normal.innerProduct( + _point.subtract(ref)); + return ref.add(_normal.scale(lambda)); + } + + /** + * Returns normalized coordinates within the plane of the projection of a point. + */ + public Pair normalizedProjection(Point aPoint) { + Coordinates projection = project(aPoint); + Coordinates delta = projection.subtract(_point); + double x1 = delta.innerProduct(_north); + double x2 = delta.innerProduct(_east); + return new Pair(x1, x2); + } +} diff --git a/gps/src/org/wamblee/gps/geometry/Point.java b/gps/src/org/wamblee/gps/geometry/Point.java new file mode 100644 index 00000000..175bd8e0 --- /dev/null +++ b/gps/src/org/wamblee/gps/geometry/Point.java @@ -0,0 +1,66 @@ +/* + * Copyright 2006 the original author or authors. + * + * 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 org.wamblee.gps.geometry; + + +/** + * Represents a point in some coordinate system. + */ +public class Point { + + private Coordinates _coordinates; + private CoordinateSystem _system; + + /** + * Constructs the point. + * @param aCoordinates Coordinates of the point in its coordinate system. + * @param aSystem Coordinate system. + */ + public Point(Coordinates aCoordinates, CoordinateSystem aSystem) { + _coordinates = aCoordinates; + _system = aSystem; + } + + /** + * Gets the coordinates in the point's coordinate system. + * @return Coordinates. + */ + public Coordinates getCoordinates() { + return _coordinates; + } + + public Coordinates getReferenceCoordinates() { + return _system.toReferenceSystem(_coordinates); + } + + /** + * Gets the coordinate system. + * @return Coordinate system. + */ + public CoordinateSystem getCoordinateSystem() { + return _system; + } + + + /* (non-Javadoc) + * @see java.lang.Object#toString() + */ + @Override + public String toString() { + return getCoordinates().toString(); + } +} diff --git a/gps/src/org/wamblee/gps/geometry/ReferenceCoordinateSystem.java b/gps/src/org/wamblee/gps/geometry/ReferenceCoordinateSystem.java new file mode 100644 index 00000000..6d249313 --- /dev/null +++ b/gps/src/org/wamblee/gps/geometry/ReferenceCoordinateSystem.java @@ -0,0 +1,70 @@ +/* + * Copyright 2006 the original author or authors. + * + * 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 org.wamblee.gps.geometry; + + +/** + * Reference coordinate system which is the basis for defining metrics. + * This is a Cartesian coordinate system. + */ +public class ReferenceCoordinateSystem implements CoordinateSystem { + + /** + * Constructs the coordinate system. + * + */ + public ReferenceCoordinateSystem() { + // Empty + } + + /* + * (non-Javadoc) + * + * @see org.wamblee.gpx.CoordinateSystem#toReferenceSystem(org.wamblee.gpx.Coordinates) + */ + public Coordinates toReferenceSystem(Coordinates aCoordinates) { + return aCoordinates; + } + + /* + * (non-Javadoc) + * + * @see org.wamblee.gpx.CoordinateSystem#distance(org.wamblee.gpx.Coordinates, + * org.wamblee.gpx.Coordinates) + */ + private static double distance(Coordinates aC1, Coordinates aC2) { + return Math.sqrt(square(aC1.getX1() - aC2.getX1()) + + square(aC1.getX2() - aC2.getX2()) + + square(aC1.getX3() - aC2.getX3())); + } + + private static double square(double x) { + return x * x; + } + + /** + * Computes the distance between two points in arbitrary coordinate systems. + * @param aP1 First point. + * @param aP2 Second point. + * @return Distance. + */ + public static double distance(Point aP1, Point aP2) { + return distance( aP1.getCoordinateSystem().toReferenceSystem(aP1.getCoordinates()), + aP2.getCoordinateSystem().toReferenceSystem(aP2.getCoordinates())); + } + +} diff --git a/gps/src/org/wamblee/gps/geometry/SphericalCoordinateSystem.java b/gps/src/org/wamblee/gps/geometry/SphericalCoordinateSystem.java new file mode 100644 index 00000000..d62cef88 --- /dev/null +++ b/gps/src/org/wamblee/gps/geometry/SphericalCoordinateSystem.java @@ -0,0 +1,61 @@ +/* + * Copyright 2006 the original author or authors. + * + * 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 org.wamblee.gps.geometry; + +import static java.lang.Math.PI; +import static java.lang.Math.cos; +import static java.lang.Math.sin; + + +/** + * Represents the coordinate system for a GPS measurement identified by + *
    + *
  • x1: latitude in degrees
    • + *
  • x2: longitude in degrees
    • + *
  • x3: elevation in meters
    • + *
+ * This coordinate system models the earth as a sphere of a specific radius. + */ +public class SphericalCoordinateSystem implements CoordinateSystem { + /** + * Earth radius in meters. + */ + private static final double EARTH_RADIUS = 6371000; + + + /* (non-Javadoc) + * @see org.wamblee.gpx.CoordinateSystem#toReferenceSystem(org.wamblee.gpx.Coordinates) + */ + public Coordinates toReferenceSystem(Coordinates aCoordinates) { + double latrad = radians(aCoordinates.getX1()); + double lonrad = radians(aCoordinates.getX2()); + double coslat = cos(latrad); + double sinlat = sin(latrad); + double coslon = cos(lonrad); + double sinlon = sin(lonrad); + + double trueElevation = EARTH_RADIUS + aCoordinates.getX3(); + return new Coordinates(trueElevation*coslat*coslon, + trueElevation*coslat*sinlon, + trueElevation*sinlat); + + } + + private double radians(double aDegrees) { + return aDegrees/180.0*PI; + } +} diff --git a/gps/src/org/wamblee/gps/geometry/Wgs84CoordinateSystem.java b/gps/src/org/wamblee/gps/geometry/Wgs84CoordinateSystem.java new file mode 100644 index 00000000..38b0fcc6 --- /dev/null +++ b/gps/src/org/wamblee/gps/geometry/Wgs84CoordinateSystem.java @@ -0,0 +1,73 @@ +/* + * Copyright 2006 the original author or authors. + * + * 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 org.wamblee.gps.geometry; + +import static java.lang.Math.PI; +import static java.lang.Math.cos; +import static java.lang.Math.sin; + + +/** + * Represents the WGS 84 coordinate system for a GPS measurement identified by + *
    + *
  • x1: latitude in degrees
    • + *
  • x2: longitude in degrees
    • + *
  • x3: elevation in meters
    • + *
+ * WGS84 models the earth as an ellipse. + */ +public class Wgs84CoordinateSystem implements CoordinateSystem { + /* + * Ellipsoide parameters, where the ellipsoide is defined by + * + * (x^2 + y^2)/a^2 + z^2/b^2 = 1 + */ + + /** + * The radius of the ellipse at the equator + */ + private static final double A = 6378137.000; + + /** + * The distance of the North and South poles to the center of the ellipsoide. + */ + private static final double B = 6356752.314; + + + /* (non-Javadoc) + * @see org.wamblee.gpx.CoordinateSystem#toReferenceSystem(org.wamblee.gpx.Coordinates) + */ + public Coordinates toReferenceSystem(Coordinates aCoordinates) { + double latrad = radians(aCoordinates.getX1()); + double lonrad = radians(aCoordinates.getX2()); + double coslat = cos(latrad); + double sinlat = sin(latrad); + double coslon = cos(lonrad); + double sinlon = sin(lonrad); + + double r = A*B/Math.sqrt(B*B*coslat*coslat + A*A*sinlat*sinlat) + aCoordinates.getX3(); + + return new Coordinates(r*coslat*coslon, + r*coslat*sinlon, + r*sinlat); + + } + + private double radians(double aDegrees) { + return aDegrees/180.0*PI; + } +}