ucar.unidata.geoloc.projection.Orthographic Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of cdm Show documentation
Show all versions of cdm Show documentation
The NetCDF-Java Library is a Java interface to NetCDF files,
as well as to many other types of scientific data formats.
The newest version!
/*
* Copyright 1998-2009 University Corporation for Atmospheric Research/Unidata
*
* Portions of this software were developed by the Unidata Program at the
* University Corporation for Atmospheric Research.
*
* Access and use of this software shall impose the following obligations
* and understandings on the user. The user is granted the right, without
* any fee or cost, to use, copy, modify, alter, enhance and distribute
* this software, and any derivative works thereof, and its supporting
* documentation for any purpose whatsoever, provided that this entire
* notice appears in all copies of the software, derivative works and
* supporting documentation. Further, UCAR requests that the user credit
* UCAR/Unidata in any publications that result from the use of this
* software or in any product that includes this software. The names UCAR
* and/or Unidata, however, may not be used in any advertising or publicity
* to endorse or promote any products or commercial entity unless specific
* written permission is obtained from UCAR/Unidata. The user also
* understands that UCAR/Unidata is not obligated to provide the user with
* any support, consulting, training or assistance of any kind with regard
* to the use, operation and performance of this software nor to provide
* the user with any updates, revisions, new versions or "bug fixes."
*
* THIS SOFTWARE IS PROVIDED BY UCAR/UNIDATA "AS IS" AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL UCAR/UNIDATA BE LIABLE FOR ANY SPECIAL,
* INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING
* FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
* NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION
* WITH THE ACCESS, USE OR PERFORMANCE OF THIS SOFTWARE.
*/
package ucar.unidata.geoloc.projection;
import ucar.nc2.constants.CF;
import ucar.unidata.geoloc.*;
/**
* Orthographic Projection spherical earth.
*
* See John Snyder, Map Projections used by the USGS, Bulletin 1532,
* 2nd edition (1983), p 145
*
* @author Unidata Development Team
* @see Projection
* @see ProjectionImpl
*/
public class Orthographic extends ProjectionImpl {
private double lat0, lon0; // center lat/lon in radians
private final double R; // radius
/**
* constants from Snyder's equations
*/
private double lon0Degrees;
private double cosLat0, sinLat0;
@Override
public ProjectionImpl constructCopy() {
ProjectionImpl result = new Orthographic(getOriginLat(), getOriginLon(), R);
result.setDefaultMapArea(defaultMapArea);
result.setName(name);
return result;
}
/**
* Constructor with default parameters
*/
public Orthographic() {
this(0.0, 0.0);
}
/**
* Construct a Orthographic Projection.
*
* @param lat0 lat origin of the coord. system on the projection plane
* @param lon0 lon origin of the coord. system on the projection plane
* @throws IllegalArgumentException
*/
public Orthographic(double lat0, double lon0) {
this(lat0, lon0, EARTH_RADIUS);
}
/**
* Construct a Orthographic Projection, specify earth radius
*
* @param lat0 lat origin of the coord. system on the projection plane
* @param lon0 lon origin of the coord. system on the projection plane
* @param earthRadius radius of the earth
* @throws IllegalArgumentException if lat0, par1, par2 = +/-90 deg
*/
public Orthographic(double lat0, double lon0, double earthRadius) {
super("Orthographic", false);
this.lat0 = Math.toRadians(lat0);
this.lon0 = Math.toRadians(lon0);
R = earthRadius;
precalculate();
addParameter(CF.GRID_MAPPING_NAME, CF.ORTHOGRAPHIC);
addParameter(CF.LATITUDE_OF_PROJECTION_ORIGIN, lat0);
addParameter(CF.LONGITUDE_OF_PROJECTION_ORIGIN, lon0);
addParameter(CF.EARTH_RADIUS, earthRadius * 1000);
}
// move this to ucar.unit or ucar.unidata.util
/**
* Precalculate some stuff
*/
private void precalculate() {
sinLat0 = Math.sin(lat0);
cosLat0 = Math.cos(lat0);
lon0Degrees = Math.toDegrees(lon0);
}
@Override
public boolean equals(Object o) {
if (this == o) return true;
if (o == null || getClass() != o.getClass()) return false;
Orthographic that = (Orthographic) o;
if (Double.compare(that.R, R) != 0) return false;
if (Double.compare(that.lat0, lat0) != 0) return false;
if (Double.compare(that.lon0, lon0) != 0) return false;
if ((defaultMapArea == null) != (that.defaultMapArea == null)) return false; // common case is that these are null
if (defaultMapArea != null && !that.defaultMapArea.equals(defaultMapArea)) return false;
return true;
}
@Override
public int hashCode() {
int result;
long temp;
temp = lat0 != +0.0d ? Double.doubleToLongBits(lat0) : 0L;
result = (int) (temp ^ (temp >>> 32));
temp = lon0 != +0.0d ? Double.doubleToLongBits(lon0) : 0L;
result = 31 * result + (int) (temp ^ (temp >>> 32));
temp = R != +0.0d ? Double.doubleToLongBits(R) : 0L;
result = 31 * result + (int) (temp ^ (temp >>> 32));
return result;
}
// bean properties
/**
* Get the origin longitude in degrees
*
* @return the origin longitude.
*/
public double getOriginLon() {
return Math.toDegrees(lon0);
}
/**
* Get the origin latitude in degrees
*
* @return the origin latitude.
*/
public double getOriginLat() {
return Math.toDegrees(lat0);
}
//////////////////////////////////////////////
// setters for IDV serialization - do not use except for object creating
/**
* Set the origin longitude.
* @param lon the origin longitude.
*/
public void setOriginLon(double lon) {
lon0 = Math.toRadians(lon);
precalculate();
}
/**
* Set the origin latitude.
*
* @param lat the origin latitude.
*/
public void setOriginLat(double lat) {
lat0 = Math.toRadians(lat);
precalculate();
}
//////////////////////////////////////////////
/**
* Get the label to be used in the gui for this type of projection
*
* @return Type label
*/
public String getProjectionTypeLabel() {
return "Orthographic";
}
/**
* Create a String of the parameters.
*
* @return a String of the parameters
*/
public String paramsToString() {
return toString();
}
@Override
public String toString() {
return "Orthographic{" +
"lat0=" + lat0 +
", lon0=" + lon0 +
", R=" + R +
'}';
}
/**
* This returns true when the line between pt1 and pt2 crosses the seam.
* When the cone is flattened, the "seam" is lon0 +- 180.
*
* @param pt1 point 1
* @param pt2 point 2
* @return true when the line between pt1 and pt2 crosses the seam.
*/
public boolean crossSeam(ProjectionPoint pt1, ProjectionPoint pt2) {
// either point is infinite
if (ProjectionPointImpl.isInfinite(pt1) || ProjectionPointImpl.isInfinite(pt2))
return true;
// opposite signed X values, larger then 5000 km
return (pt1.getX() * pt2.getX() < 0) && (Math.abs(pt1.getX() - pt2.getX()) > 5000.0);
}
/*MACROBODY
latLonToProj {} {
fromLat = Math.toRadians(fromLat);
double lonDiff =
Math.toRadians(LatLonPointImpl.lonNormal(fromLon-lon0Degrees));
double cosc = sinLat0*Math.sin(fromLat) + cosLat0*Math.cos(fromLat)*Math.cos(lonDiff);
if (cosc >= 0) {
toX = R*Math.cos(fromLat)*Math.sin(lonDiff);
toY = R*(cosLat0*Math.sin(fromLat) - sinLat0*Math.cos(fromLat)*Math.cos(lonDiff));
} else {
toX = Double.POSITIVE_INFINITY;
toY = Double.POSITIVE_INFINITY;
}
}
projToLatLon {} {
fromX = fromX;
fromY = fromY;
double rho = Math.sqrt(fromX*fromX + fromY*fromY);
double c = Math.asin(rho/R);
toLon = lon0;
double temp = 0;
if (Math.abs(rho) > TOLERANCE) {
toLat = Math.asin(Math.cos(c)*sinLat0 + (fromY*Math.sin(c)*cosLat0/rho));
if (Math.abs(lat0 - PI_OVER_4) > TOLERANCE) { // not 90 or -90
temp = rho*cosLat0*Math.cos(c) - fromY*sinLat0*Math.sin(c);
toLon = lon0 + Math.atan(fromX*Math.sin(c)/temp);
} else if (lat0 == PI_OVER_4) {
toLon = lon0 + Math.atan(fromX/-fromY);
temp = -fromY;
} else {
toLon = lon0 + Math.atan(fromX/fromY);
temp = fromY;
}
} else {
toLat = lat0;
}
toLat= Math.toDegrees(toLat);
toLon= Math.toDegrees(toLon);
if (temp < 0) toLon += 180;
toLon= LatLonPointImpl.lonNormal(toLon);
}
MACROBODY*/
/*BEGINGENERATED*/
/*
Note this section has been generated using the convert.tcl script.
This script, run as:
tcl convert.tcl Orthographic.java
takes the actual projection conversion code defined in the MACROBODY
section above and generates the following 6 methods
*/
/**
* Convert a LatLonPoint to projection coordinates
*
* @param latLon convert from these lat, lon coordinates
* @param result the object to write to
* @return the given result
*/
public ProjectionPoint latLonToProj(LatLonPoint latLon,
ProjectionPointImpl result) {
double toX, toY;
double fromLat = latLon.getLatitude();
double fromLon = latLon.getLongitude();
fromLat = Math.toRadians(fromLat);
double lonDiff = Math.toRadians(LatLonPointImpl.lonNormal(fromLon - lon0Degrees));
double cosc = sinLat0 * Math.sin(fromLat) + cosLat0 * Math.cos(fromLat) * Math.cos(lonDiff);
if (cosc >= 0) {
toX = R * Math.cos(fromLat) * Math.sin(lonDiff);
toY = R * (cosLat0 * Math.sin(fromLat) - sinLat0 * Math.cos(fromLat) * Math.cos(lonDiff));
} else {
toX = Double.POSITIVE_INFINITY;
toY = Double.POSITIVE_INFINITY;
}
result.setLocation(toX, toY);
return result;
}
/**
* Convert projection coordinates to a LatLonPoint
* Note: a new object is not created on each call for the return value.
*
* @param world convert from these projection coordinates
* @param result the object to write to
* @return LatLonPoint convert to these lat/lon coordinates
*/
public LatLonPoint projToLatLon(ProjectionPoint world, LatLonPointImpl result) {
double toLat, toLon;
double fromX = world.getX();
double fromY = world.getY();
double rho = Math.sqrt(fromX * fromX + fromY * fromY);
double c = Math.asin(rho / R);
toLon = lon0;
double temp = 0;
if (Math.abs(rho) > TOLERANCE) {
toLat = Math.asin(Math.cos(c) * sinLat0
+ (fromY * Math.sin(c) * cosLat0 / rho));
if (Math.abs(lat0 - PI_OVER_4) > TOLERANCE) { // not 90 or -90
temp = rho * cosLat0 * Math.cos(c)
- fromY * sinLat0 * Math.sin(c);
toLon = lon0 + Math.atan(fromX * Math.sin(c) / temp);
} else if (Double.compare(lat0, PI_OVER_4) == 0) {
toLon = lon0 + Math.atan(fromX / -fromY);
temp = -fromY;
} else {
toLon = lon0 + Math.atan(fromX / fromY);
temp = fromY;
}
} else {
toLat = lat0;
}
toLat = Math.toDegrees(toLat);
toLon = Math.toDegrees(toLon);
if (temp < 0) {
toLon += 180;
}
toLon = LatLonPointImpl.lonNormal(toLon);
result.setLatitude(toLat);
result.setLongitude(toLon);
return result;
}
/**
* Convert lat/lon coordinates to projection coordinates.
*
* @param from array of lat/lon coordinates: from[2][n],
* where from[0][i], from[1][i] is the (lat,lon)
* coordinate of the ith point
* @param to resulting array of projection coordinates,
* where to[0][i], to[1][i] is the (x,y) coordinate
* of the ith point
* @param latIndex index of latitude in "from"
* @param lonIndex index of longitude in "from"
* @return the "to" array.
*/
public float[][] latLonToProj(float[][] from, float[][] to, int latIndex,
int lonIndex) {
int cnt = from[0].length;
float[] fromLatA = from[latIndex];
float[] fromLonA = from[lonIndex];
float[] resultXA = to[INDEX_X];
float[] resultYA = to[INDEX_Y];
double toX, toY;
for (int i = 0; i < cnt; i++) {
double fromLat = fromLatA[i];
double fromLon = fromLonA[i];
fromLat = Math.toRadians(fromLat);
double lonDiff = Math.toRadians(LatLonPointImpl.lonNormal(fromLon
- lon0Degrees));
double cosc = sinLat0 * Math.sin(fromLat)
+ cosLat0 * Math.cos(fromLat) * Math.cos(lonDiff);
if (cosc >= 0) {
toX = R * Math.cos(fromLat) * Math.sin(lonDiff);
toY = R * (cosLat0 * Math.sin(fromLat)
- sinLat0 * Math.cos(fromLat) * Math.cos(lonDiff));
} else {
toX = Double.POSITIVE_INFINITY;
toY = Double.POSITIVE_INFINITY;
}
resultXA[i] = (float) toX;
resultYA[i] = (float) toY;
}
return to;
}
/**
* Convert lat/lon coordinates to projection coordinates.
*
* @param from array of lat/lon coordinates: from[2][n], where
* (from[0][i], from[1][i]) is the (lat,lon) coordinate
* of the ith point
* @param to resulting array of projection coordinates: to[2][n]
* where (to[0][i], to[1][i]) is the (x,y) coordinate
* of the ith point
* @return the "to" array
*/
public float[][] projToLatLon(float[][] from, float[][] to) {
int cnt = from[0].length;
float[] fromXA = from[INDEX_X];
float[] fromYA = from[INDEX_Y];
float[] toLatA = to[INDEX_LAT];
float[] toLonA = to[INDEX_LON];
double toLat, toLon;
for (int i = 0; i < cnt; i++) {
double fromX = fromXA[i];
double fromY = fromYA[i];
double rho = Math.sqrt(fromX * fromX + fromY * fromY);
double c = Math.asin(rho / R);
toLon = lon0;
double temp = 0;
if (Math.abs(rho) > TOLERANCE) {
toLat = Math.asin(Math.cos(c) * sinLat0
+ (fromY * Math.sin(c) * cosLat0 / rho));
if (Math.abs(lat0 - PI_OVER_4) > TOLERANCE) { // not 90 or -90
temp = rho * cosLat0 * Math.cos(c)
- fromY * sinLat0 * Math.sin(c);
toLon = lon0 + Math.atan(fromX * Math.sin(c) / temp);
} else if (Double.compare(lat0, PI_OVER_4) == 0) {
toLon = lon0 + Math.atan(fromX / -fromY);
temp = -fromY;
} else {
toLon = lon0 + Math.atan(fromX / fromY);
temp = fromY;
}
} else {
toLat = lat0;
}
toLat = Math.toDegrees(toLat);
toLon = Math.toDegrees(toLon);
if (temp < 0) {
toLon += 180;
}
toLon = LatLonPointImpl.lonNormal(toLon);
toLatA[i] = (float) toLat;
toLonA[i] = (float) toLon;
}
return to;
}
/**
* Convert lat/lon coordinates to projection coordinates.
*
* @param from array of lat/lon coordinates: from[2][n],
* where from[0][i], from[1][i] is the (lat,lon)
* coordinate of the ith point
* @param to resulting array of projection coordinates,
* where to[0][i], to[1][i] is the (x,y) coordinate
* of the ith point
* @param latIndex index of latitude in "from"
* @param lonIndex index of longitude in "from"
* @return the "to" array.
*/
public double[][] latLonToProj(double[][] from, double[][] to,
int latIndex, int lonIndex) {
int cnt = from[0].length;
double[] fromLatA = from[latIndex];
double[] fromLonA = from[lonIndex];
double[] resultXA = to[INDEX_X];
double[] resultYA = to[INDEX_Y];
double toX, toY;
for (int i = 0; i < cnt; i++) {
double fromLat = fromLatA[i];
double fromLon = fromLonA[i];
fromLat = Math.toRadians(fromLat);
double lonDiff = Math.toRadians(LatLonPointImpl.lonNormal(fromLon
- lon0Degrees));
double cosc = sinLat0 * Math.sin(fromLat)
+ cosLat0 * Math.cos(fromLat) * Math.cos(lonDiff);
if (cosc >= 0) {
toX = R * Math.cos(fromLat) * Math.sin(lonDiff);
toY = R * (cosLat0 * Math.sin(fromLat)
- sinLat0 * Math.cos(fromLat) * Math.cos(lonDiff));
} else {
toX = Double.POSITIVE_INFINITY;
toY = Double.POSITIVE_INFINITY;
}
resultXA[i] = toX;
resultYA[i] = toY;
}
return to;
}
/**
* Convert lat/lon coordinates to projection coordinates.
*
* @param from array of lat/lon coordinates: from[2][n], where
* (from[0][i], from[1][i]) is the (lat,lon) coordinate
* of the ith point
* @param to resulting array of projection coordinates: to[2][n]
* where (to[0][i], to[1][i]) is the (x,y) coordinate
* of the ith point
* @return the "to" array
*/
public double[][] projToLatLon(double[][] from, double[][] to) {
int cnt = from[0].length;
double[] fromXA = from[INDEX_X];
double[] fromYA = from[INDEX_Y];
double[] toLatA = to[INDEX_LAT];
double[] toLonA = to[INDEX_LON];
double toLat, toLon;
for (int i = 0; i < cnt; i++) {
double fromX = fromXA[i];
double fromY = fromYA[i];
double rho = Math.sqrt(fromX * fromX + fromY * fromY);
double c = Math.asin(rho / R);
toLon = lon0;
double temp = 0;
if (Math.abs(rho) > TOLERANCE) {
toLat = Math.asin(Math.cos(c) * sinLat0
+ (fromY * Math.sin(c) * cosLat0 / rho));
if (Math.abs(lat0 - PI_OVER_4) > TOLERANCE) { // not 90 or -90
temp = rho * cosLat0 * Math.cos(c)
- fromY * sinLat0 * Math.sin(c);
toLon = lon0 + Math.atan(fromX * Math.sin(c) / temp);
} else if (Double.compare(lat0, PI_OVER_4) == 0) {
toLon = lon0 + Math.atan(fromX / -fromY);
temp = -fromY;
} else {
toLon = lon0 + Math.atan(fromX / fromY);
temp = fromY;
}
} else {
toLat = lat0;
}
toLat = Math.toDegrees(toLat);
toLon = Math.toDegrees(toLon);
if (temp < 0) {
toLon += 180;
}
toLon = LatLonPointImpl.lonNormal(toLon);
toLatA[i] = toLat;
toLonA[i] = toLon;
}
return to;
}
/*ENDGENERATED*/
/**
* Test
*
* @param args not used
*/
public static void main(String[] args) {
Orthographic a = new Orthographic(40, -100);
ProjectionPoint p = a.latLonToProj(30, -110);
System.out.println("proj point = " + p);
LatLonPoint ll = a.projToLatLon(p);
System.out.println("ll = " + ll);
}
}
© 2015 - 2024 Weber Informatics LLC | Privacy Policy