source: josm/trunk/src/org/openstreetmap/josm/data/coor/LatLon.java@ 9243

Last change on this file since 9243 was 9243, checked in by Don-vip, 8 years ago

javadoc update
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1// License: GPL. For details, see LICENSE file.
2package org.openstreetmap.josm.data.coor;
3
4import static java.lang.Math.PI;
5import static java.lang.Math.asin;
6import static java.lang.Math.atan2;
7import static java.lang.Math.cos;
8import static java.lang.Math.sin;
9import static java.lang.Math.sqrt;
10import static java.lang.Math.toRadians;
11import static org.openstreetmap.josm.tools.I18n.trc;
12
13import java.awt.geom.Area;
14import java.text.DecimalFormat;
15import java.text.NumberFormat;
16import java.util.Arrays;
17import java.util.Locale;
18
19import org.openstreetmap.gui.jmapviewer.interfaces.ICoordinate;
20import org.openstreetmap.josm.Main;
21import org.openstreetmap.josm.data.Bounds;
22import org.openstreetmap.josm.tools.Utils;
23
24/**
25 * LatLon are unprojected latitude / longitude coordinates.
26 * <br>
27 * <b>Latitude</b> specifies the north-south position in degrees
28 * where valid values are in the [-90,90] and positive values specify positions north of the equator.
29 * <br>
30 * <b>Longitude</b> specifies the east-west position in degrees
31 * where valid values are in the [-180,180] and positive values specify positions east of the prime meridian.
32 * <br>
33 * <img alt="lat/lon" src="https://upload.wikimedia.org/wikipedia/commons/6/62/Latitude_and_Longitude_of_the_Earth.svg">
34 * <br>
35 * This class is immutable.
36 *
37 * @author Imi
38 */
39public class LatLon extends Coordinate {
40
41 private static final long serialVersionUID = 1L;
42
43 /**
44 * Minimum difference in location to not be represented as the same position.
45 * The API returns 7 decimals.
46 */
47 public static final double MAX_SERVER_PRECISION = 1e-7;
48 public static final double MAX_SERVER_INV_PRECISION = 1e7;
49 public static final int MAX_SERVER_DIGITS = 7;
50
51 /**
52 * The (0,0) coordinates.
53 * @since 6178
54 */
55 public static final LatLon ZERO = new LatLon(0, 0);
56
57 private static DecimalFormat cDmsMinuteFormatter = new DecimalFormat("00");
58 private static DecimalFormat cDmsSecondFormatter = new DecimalFormat("00.0");
59 private static DecimalFormat cDmMinuteFormatter = new DecimalFormat("00.000");
60 public static final DecimalFormat cDdFormatter;
61 public static final DecimalFormat cDdHighPecisionFormatter;
62 static {
63 // Don't use the localized decimal separator. This way we can present
64 // a comma separated list of coordinates.
65 cDdFormatter = (DecimalFormat) NumberFormat.getInstance(Locale.UK);
66 cDdFormatter.applyPattern("###0.0######");
67 cDdHighPecisionFormatter = (DecimalFormat) NumberFormat.getInstance(Locale.UK);
68 cDdHighPecisionFormatter.applyPattern("###0.0##########");
69 }
70
71 private static final String cDms60 = cDmsSecondFormatter.format(60.0);
72 private static final String cDms00 = cDmsSecondFormatter.format(0.0);
73 private static final String cDm60 = cDmMinuteFormatter.format(60.0);
74 private static final String cDm00 = cDmMinuteFormatter.format(0.0);
75
76 /**
77 * Replies true if lat is in the range [-90,90]
78 *
79 * @param lat the latitude
80 * @return true if lat is in the range [-90,90]
81 */
82 public static boolean isValidLat(double lat) {
83 return lat >= -90d && lat <= 90d;
84 }
85
86 /**
87 * Replies true if lon is in the range [-180,180]
88 *
89 * @param lon the longitude
90 * @return true if lon is in the range [-180,180]
91 */
92 public static boolean isValidLon(double lon) {
93 return lon >= -180d && lon <= 180d;
94 }
95
96 /**
97 * Replies true if lat is in the range [-90,90] and lon is in the range [-180,180]
98 *
99 * @return true if lat is in the range [-90,90] and lon is in the range [-180,180]
100 */
101 public boolean isValid() {
102 return isValidLat(lat()) && isValidLon(lon());
103 }
104
105 public static double toIntervalLat(double value) {
106 if (value < -90)
107 return -90;
108 if (value > 90)
109 return 90;
110 return value;
111 }
112
113 /**
114 * Returns a valid OSM longitude [-180,+180] for the given extended longitude value.
115 * For example, a value of -181 will return +179, a value of +181 will return -179.
116 * @param value A longitude value not restricted to the [-180,+180] range.
117 * @return a valid OSM longitude [-180,+180]
118 */
119 public static double toIntervalLon(double value) {
120 if (isValidLon(value))
121 return value;
122 else {
123 int n = (int) (value + Math.signum(value)*180.0) / 360;
124 return value - n*360.0;
125 }
126 }
127
128 /**
129 * Replies the coordinate in degrees/minutes/seconds format
130 * @param pCoordinate The coordinate to convert
131 * @return The coordinate in degrees/minutes/seconds format
132 */
133 public static String dms(double pCoordinate) {
134
135 double tAbsCoord = Math.abs(pCoordinate);
136 int tDegree = (int) tAbsCoord;
137 double tTmpMinutes = (tAbsCoord - tDegree) * 60;
138 int tMinutes = (int) tTmpMinutes;
139 double tSeconds = (tTmpMinutes - tMinutes) * 60;
140
141 String sDegrees = Integer.toString(tDegree);
142 String sMinutes = cDmsMinuteFormatter.format(tMinutes);
143 String sSeconds = cDmsSecondFormatter.format(tSeconds);
144
145 if (cDms60.equals(sSeconds)) {
146 sSeconds = cDms00;
147 sMinutes = cDmsMinuteFormatter.format(tMinutes+1);
148 }
149 if ("60".equals(sMinutes)) {
150 sMinutes = "00";
151 sDegrees = Integer.toString(tDegree+1);
152 }
153
154 return sDegrees + '\u00B0' + sMinutes + '\'' + sSeconds + '\"';
155 }
156
157 /**
158 * Replies the coordinate in degrees/minutes format
159 * @param pCoordinate The coordinate to convert
160 * @return The coordinate in degrees/minutes format
161 */
162 public static String dm(double pCoordinate) {
163
164 double tAbsCoord = Math.abs(pCoordinate);
165 int tDegree = (int) tAbsCoord;
166 double tMinutes = (tAbsCoord - tDegree) * 60;
167
168 String sDegrees = Integer.toString(tDegree);
169 String sMinutes = cDmMinuteFormatter.format(tMinutes);
170
171 if (sMinutes.equals(cDm60)) {
172 sMinutes = cDm00;
173 sDegrees = Integer.toString(tDegree+1);
174 }
175
176 return sDegrees + '\u00B0' + sMinutes + '\'';
177 }
178
179 /**
180 * Constructs a new {@link LatLon}
181 * @param lat the latitude, i.e., the north-south position in degrees
182 * @param lon the longitude, i.e., the east-west position in degrees
183 */
184 public LatLon(double lat, double lon) {
185 super(lon, lat);
186 }
187
188 protected LatLon(LatLon coor) {
189 super(coor.lon(), coor.lat());
190 }
191
192 public LatLon(ICoordinate coor) {
193 this(coor.getLat(), coor.getLon());
194 }
195
196
197 /**
198 * Returns the latitude, i.e., the north-south position in degrees.
199 * @return the latitude
200 */
201 public double lat() {
202 return y;
203 }
204
205 public static final String SOUTH = trc("compass", "S");
206 public static final String NORTH = trc("compass", "N");
207
208 public String latToString(CoordinateFormat d) {
209 switch(d) {
210 case DECIMAL_DEGREES: return cDdFormatter.format(y);
211 case DEGREES_MINUTES_SECONDS: return dms(y) + ((y < 0) ? SOUTH : NORTH);
212 case NAUTICAL: return dm(y) + ((y < 0) ? SOUTH : NORTH);
213 case EAST_NORTH: return cDdFormatter.format(Main.getProjection().latlon2eastNorth(this).north());
214 default: return "ERR";
215 }
216 }
217
218 /**
219 * Returns the longitude, i.e., the east-west position in degrees.
220 * @return the longitude
221 */
222 public double lon() {
223 return x;
224 }
225
226 public static final String WEST = trc("compass", "W");
227 public static final String EAST = trc("compass", "E");
228
229 public String lonToString(CoordinateFormat d) {
230 switch(d) {
231 case DECIMAL_DEGREES: return cDdFormatter.format(x);
232 case DEGREES_MINUTES_SECONDS: return dms(x) + ((x < 0) ? WEST : EAST);
233 case NAUTICAL: return dm(x) + ((x < 0) ? WEST : EAST);
234 case EAST_NORTH: return cDdFormatter.format(Main.getProjection().latlon2eastNorth(this).east());
235 default: return "ERR";
236 }
237 }
238
239 /**
240 * @param other other lat/lon
241 * @return <code>true</code> if the other point has almost the same lat/lon
242 * values, only differing by no more than 1 / {@link #MAX_SERVER_PRECISION MAX_SERVER_PRECISION}.
243 */
244 public boolean equalsEpsilon(LatLon other) {
245 double p = MAX_SERVER_PRECISION / 2;
246 return Math.abs(lat()-other.lat()) <= p && Math.abs(lon()-other.lon()) <= p;
247 }
248
249 /**
250 * Determines if this lat/lon is outside of the world
251 * @return <code>true</code>, if the coordinate is outside the world, compared by using lat/lon.
252 */
253 public boolean isOutSideWorld() {
254 Bounds b = Main.getProjection().getWorldBoundsLatLon();
255 return lat() < b.getMinLat() || lat() > b.getMaxLat() ||
256 lon() < b.getMinLon() || lon() > b.getMaxLon();
257 }
258
259 /**
260 * Determines if this lat/lon is within the given bounding box.
261 * @param b bounding box
262 * @return <code>true</code> if this is within the given bounding box.
263 */
264 public boolean isWithin(Bounds b) {
265 return b.contains(this);
266 }
267
268 /**
269 * Check if this is contained in given area or area is null.
270 *
271 * @param a Area
272 * @return <code>true</code> if this is contained in given area or area is null.
273 */
274 public boolean isIn(Area a) {
275 return a == null || a.contains(x, y);
276 }
277
278 /**
279 * Computes the distance between this lat/lon and another point on the earth.
280 * Uses Haversine formular.
281 * @param other the other point.
282 * @return distance in metres.
283 */
284 public double greatCircleDistance(LatLon other) {
285 double R = 6378135;
286 double sinHalfLat = sin(toRadians(other.lat() - this.lat()) / 2);
287 double sinHalfLon = sin(toRadians(other.lon() - this.lon()) / 2);
288 double d = 2 * R * asin(
289 sqrt(sinHalfLat*sinHalfLat +
290 cos(toRadians(this.lat()))*cos(toRadians(other.lat()))*sinHalfLon*sinHalfLon));
291 // For points opposite to each other on the sphere,
292 // rounding errors could make the argument of asin greater than 1
293 // (This should almost never happen.)
294 if (java.lang.Double.isNaN(d)) {
295 Main.error("NaN in greatCircleDistance");
296 d = PI * R;
297 }
298 return d;
299 }
300
301 /**
302 * Returns the heading, in radians, that you have to use to get from this lat/lon to another.
303 *
304 * (I don't know the original source of this formula, but see
305 * <a href="https://math.stackexchange.com/questions/720/how-to-calculate-a-heading-on-the-earths-surface">this question</a>
306 * for some hints how it is derived.)
307 *
308 * @param other the "destination" position
309 * @return heading in the range 0 &lt;= hd &lt; 2*PI
310 */
311 public double heading(LatLon other) {
312 double hd = atan2(sin(toRadians(this.lon() - other.lon())) * cos(toRadians(other.lat())),
313 cos(toRadians(this.lat())) * sin(toRadians(other.lat())) -
314 sin(toRadians(this.lat())) * cos(toRadians(other.lat())) * cos(toRadians(this.lon() - other.lon())));
315 hd %= 2 * PI;
316 if (hd < 0) {
317 hd += 2 * PI;
318 }
319 return hd;
320 }
321
322 /**
323 * Returns this lat/lon pair in human-readable format.
324 *
325 * @return String in the format "lat=1.23456 deg, lon=2.34567 deg"
326 */
327 public String toDisplayString() {
328 NumberFormat nf = NumberFormat.getInstance();
329 nf.setMaximumFractionDigits(5);
330 return "lat=" + nf.format(lat()) + "\u00B0, lon=" + nf.format(lon()) + '\u00B0';
331 }
332
333 /**
334 * Returns this lat/lon pair in human-readable format separated by {@code separator}.
335 * @param separator values separator
336 * @return String in the format {@code "1.23456[separator]2.34567"}
337 */
338 public String toStringCSV(String separator) {
339 return Utils.join(separator, Arrays.asList(
340 latToString(CoordinateFormat.DECIMAL_DEGREES),
341 lonToString(CoordinateFormat.DECIMAL_DEGREES)
342 ));
343 }
344
345 public LatLon interpolate(LatLon ll2, double proportion) {
346 return new LatLon(this.lat() + proportion * (ll2.lat() - this.lat()),
347 this.lon() + proportion * (ll2.lon() - this.lon()));
348 }
349
350 public LatLon getCenter(LatLon ll2) {
351 return new LatLon((this.lat() + ll2.lat())/2.0, (this.lon() + ll2.lon())/2.0);
352 }
353
354 /**
355 * Returns the euclidean distance from this {@code LatLon} to a specified {@code LatLon}.
356 *
357 * @param ll the specified coordinate to be measured against this {@code LatLon}
358 * @return the euclidean distance from this {@code LatLon} to a specified {@code LatLon}
359 * @since 6166
360 */
361 public double distance(final LatLon ll) {
362 return super.distance(ll);
363 }
364
365 /**
366 * Returns the square of the euclidean distance from this {@code LatLon} to a specified {@code LatLon}.
367 *
368 * @param ll the specified coordinate to be measured against this {@code LatLon}
369 * @return the square of the euclidean distance from this {@code LatLon} to a specified {@code LatLon}
370 * @since 6166
371 */
372 public double distanceSq(final LatLon ll) {
373 return super.distanceSq(ll);
374 }
375
376 @Override
377 public String toString() {
378 return "LatLon[lat="+lat()+",lon="+lon()+']';
379 }
380
381 /**
382 * Returns the value rounded to OSM precisions, i.e. to {@link LatLon#MAX_SERVER_PRECISION}.
383 * @param value lat/lon value
384 *
385 * @return rounded value
386 */
387 public static double roundToOsmPrecision(double value) {
388 return Math.round(value * MAX_SERVER_INV_PRECISION) / MAX_SERVER_INV_PRECISION;
389 }
390
391 /**
392 * Returns the value rounded to OSM precision. This function is now the same as
393 * {@link #roundToOsmPrecision(double)}, since the rounding error has been fixed.
394 * @param value lat/lon value
395 *
396 * @return rounded value
397 */
398 public static double roundToOsmPrecisionStrict(double value) {
399 return roundToOsmPrecision(value);
400 }
401
402 /**
403 * Replies a clone of this lat LatLon, rounded to OSM precisions, i.e. to
404 * MAX_SERVER_PRECISION
405 *
406 * @return a clone of this lat LatLon
407 */
408 public LatLon getRoundedToOsmPrecision() {
409 return new LatLon(
410 roundToOsmPrecision(lat()),
411 roundToOsmPrecision(lon())
412 );
413 }
414
415 /**
416 * Replies a clone of this lat LatLon, rounded to OSM precisions, i.e. to
417 * MAX_SERVER_PRECISION
418 *
419 * @return a clone of this lat LatLon
420 */
421 public LatLon getRoundedToOsmPrecisionStrict() {
422 return new LatLon(
423 roundToOsmPrecisionStrict(lat()),
424 roundToOsmPrecisionStrict(lon())
425 );
426 }
427
428 @Override
429 public int hashCode() {
430 return computeHashCode(super.hashCode());
431 }
432
433 @Override
434 public boolean equals(Object obj) {
435 if (this == obj)
436 return true;
437 if (!super.equals(obj))
438 return false;
439 if (getClass() != obj.getClass())
440 return false;
441 Coordinate other = (Coordinate) obj;
442 if (java.lang.Double.doubleToLongBits(x) != java.lang.Double.doubleToLongBits(other.x))
443 return false;
444 if (java.lang.Double.doubleToLongBits(y) != java.lang.Double.doubleToLongBits(other.y))
445 return false;
446 return true;
447 }
448
449 public ICoordinate toCoordinate() {
450 return new org.openstreetmap.gui.jmapviewer.Coordinate(lat(), lon());
451 }
452}
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