Package pygeodesy :: Module sphericalTrigonometry :: Class LatLon
[frames] | no frames]

Class LatLon

           object --+                
                    |                
          bases.Named --+            
                        |            
              bases.Based --+        
                            |        
       bases.LatLonHeightBase --+    
                                |    
sphericalBase.LatLonSphericalBase --+
                                    |
                                   LatLon

New point on spherical model earth model.


Example:

>>> p = LatLon(52.205, 0.119)  # height=0

Instance Methods
 
alongTrackDistanceTo(self, start, end, radius=6371008.77141, wrap=False)
Compute the (signed) distance from the start to the closest point on the great circle path defined by a start and an end point.
 
bearingTo(self, other, wrap=False, raiser=False)
DEPRECATED, use method initialBearingTo.
 
crossingParallels(self, other, lat, wrap=False)
Return the pair of meridians at which a great circle defined by this and an other point crosses the given latitude.
 
crossTrackDistanceTo(self, start, end, radius=6371008.77141, wrap=False)
Compute the (signed) distance from this point to the great circle defined by a start and an end point.
 
destination(self, distance, bearing, radius=6371008.77141, height=None)
Locate the destination from this point after having travelled the given distance on the given initial bearing.
 
distanceTo(self, other, radius=6371008.77141, wrap=False)
Compute the distance from this to an other point.
 
greatCircle(self, bearing)
Compute the vector normal to great circle obtained by heading on the given initial bearing from this point.
 
initialBearingTo(self, other, wrap=False, raiser=False)
Compute the initial bearing (forward azimuth) from this to an other point.
 
intermediateTo(self, other, fraction, height=None, wrap=False)
Locate the point at given fraction between this and an other point.
 
intersection(self, bearing, start2, bearing2, height=None, wrap=False)
Locate the intersection of two paths each defined by a start point and an initial bearing.
 
isenclosedBy(self, points)
Check whether a (convex) polygon encloses this point.
 
isEnclosedBy(self, points)
DEPRECATED, use method isenclosedBy.
 
midpointTo(self, other, height=None, wrap=False)
Find the midpoint between this and an other point.
 
nearestOn(self, point1, point2, radius=6371008.77141, **options)
Locate the point between two points closest and this point.
 
nearestOn2(self, points, closed=False, radius=6371008.77141, **options)
Locate the point on a polygon closest to this point.
 
nearestOn3(self, points, closed=False, radius=6371008.77141, **options)
Locate the point on a polygon closest to this point.
 
toVector3d(self)
Convert this point to a vector normal to earth's surface.

Inherited from sphericalBase.LatLonSphericalBase: bearingTo2, finalBearingTo, maxLat, minLat, parse, rhumbBearingTo, rhumbDestination, rhumbDistanceTo, rhumbMidpointTo, toWm

Inherited from bases.LatLonHeightBase: __eq__, __init__, __ne__, __str__, antipode, bounds, compassAngle, compassAngleTo, copy, equals, equals3, equirectangularTo, haversineTo, isantipode, isantipodeTo, isequalTo, isequalTo3, latlon2, latlon2round, latlon_, points, points2, to2ab, to3llh, to3xyz, toStr

Inherited from bases.Based: __repr__, classof, others, toStr2

Inherited from object: __delattr__, __format__, __getattribute__, __hash__, __new__, __reduce__, __reduce_ex__, __setattr__, __sizeof__, __subclasshook__

Properties

Inherited from sphericalBase.LatLonSphericalBase: datum, isEllipsoidal, isSpherical

Inherited from bases.LatLonHeightBase: height, lat, latlon, lon

Inherited from bases.Named: classname, classnaming, name

Inherited from object: __class__

Method Details

alongTrackDistanceTo(self, start, end, radius=6371008.77141, wrap=False)

 

Compute the (signed) distance from the start to the closest point on the great circle path defined by a start and an end point.

That is, if a perpendicular is drawn from this point to the great circle path, the along-track distance is the distance from the start point to the point where the perpendicular crosses the path.

Parameters:
  • start - Start point of great circle path (LatLon).
  • end - End point of great circle path (LatLon).
  • radius - Optional, mean earth radius (meter).
  • wrap - Wrap and unroll longitudes (bool).
Returns:
Distance along the great circle path (meter, same units as radius), positive if after the start toward the end point of the path or negative if before the start point.
Raises:
  • TypeError - The start or end point is not LatLon.

Example:

>>> p = LatLon(53.2611, -0.7972)
>>> s = LatLon(53.3206, -1.7297)
>>> e = LatLon(53.1887, 0.1334)
>>> d = p.alongTrackDistanceTo(s, e)  # 62331.58

crossingParallels(self, other, lat, wrap=False)

 

Return the pair of meridians at which a great circle defined by this and an other point crosses the given latitude.

Parameters:
  • other - The other point defining great circle (LatLon).
  • lat - Latitude at the crossing (degrees).
  • wrap - Wrap and unroll longitudes (bool).
Returns:
2-Tuple (lon1, lon2) in (degrees180) or None if the great circle doesn't reach the given lat.

crossTrackDistanceTo(self, start, end, radius=6371008.77141, wrap=False)

 

Compute the (signed) distance from this point to the great circle defined by a start and an end point.

Parameters:
  • start - Start point of great circle path (LatLon).
  • end - End point of great circle path (LatLon).
  • radius - Optional, mean earth radius (meter).
  • wrap - Wrap and unroll longitudes (bool).
Returns:
Distance to great circle (negative if to the left or positive if to the right of the path).
Raises:
  • TypeError - The start or end point is not LatLon.

Example:

>>> p = LatLon(53.2611, -0.7972)
>>> s = LatLon(53.3206, -1.7297)
>>> e = LatLon(53.1887, 0.1334)
>>> d = p.crossTrackDistanceTo(s, e)  # -307.5

destination(self, distance, bearing, radius=6371008.77141, height=None)

 

Locate the destination from this point after having travelled the given distance on the given initial bearing.

Parameters:
  • distance - Distance travelled (meter, same units as radius).
  • bearing - Bearing from this point (compass degrees360).
  • radius - Optional, mean earth radius (meter).
  • height - Optional height at destination (meter, same units a radius).
Returns:
Destination point (LatLon).

Example:

>>> p1 = LatLon(51.4778, -0.0015)
>>> p2 = p1.destination(7794, 300.7)
>>> p2.toStr()  # '51.5135°N, 000.0983°W'

JS name: destinationPoint.

distanceTo(self, other, radius=6371008.77141, wrap=False)

 

Compute the distance from this to an other point.

Parameters:
  • other - The other point (LatLon).
  • radius - Optional, mean earth radius (meter).
  • wrap - Wrap and unroll longitudes (bool).
Returns:
Distance between this and the other point (meter, same units as radius).
Raises:
  • TypeError - The other point is not LatLon.

Example:

>>> p1 = LatLon(52.205, 0.119)
>>> p2 = LatLon(48.857, 2.351);
>>> d = p1.distanceTo(p2)  # 404300

greatCircle(self, bearing)

 

Compute the vector normal to great circle obtained by heading on the given initial bearing from this point.

Direction of vector is such that initial bearing vector b = c × n, where n is an n-vector representing this point.

Parameters:
  • bearing - Bearing from this point (compass degrees360).
Returns:
Vector representing great circle (Vector3d).

Example:

>>> p = LatLon(53.3206, -1.7297)
>>> g = p.greatCircle(96.0)
>>> g.toStr()  # (-0.794, 0.129, 0.594)

initialBearingTo(self, other, wrap=False, raiser=False)

 

Compute the initial bearing (forward azimuth) from this to an other point.

Parameters:
  • other - The other point (spherical LatLon).
  • wrap - Wrap and unroll longitudes (bool).
  • raiser - Optionally, raise CrossError (bool), use raiser=True for behavior like sphericalNvector.LatLon.initialBearingTo.
Returns:
Initial bearing (compass degrees360).
Raises:
  • CrossError - If this and the other point coincide, provided raiser is True and crosserrors is True.
  • TypeError - The other point is not LatLon.

Example:

>>> p1 = LatLon(52.205, 0.119)
>>> p2 = LatLon(48.857, 2.351)
>>> b = p1.initialBearingTo(p2)  # 156.2

JS name: bearingTo.

intermediateTo(self, other, fraction, height=None, wrap=False)

 

Locate the point at given fraction between this and an other point.

Parameters:
  • other - The other point (LatLon).
  • fraction - Fraction between both points (float, 0.0 = this point, 1.0 = the other point).
  • height - Optional height, overriding the fractional height (meter).
  • wrap - Wrap and unroll longitudes (bool).
Returns:
Intermediate point (LatLon).
Raises:
  • TypeError - The other point is not LatLon.

Example:

>>> p1 = LatLon(52.205, 0.119)
>>> p2 = LatLon(48.857, 2.351)
>>> p = p1.intermediateTo(p2, 0.25)  # 51.3721°N, 000.7073°E

JS name: intermediatePointTo.

intersection(self, bearing, start2, bearing2, height=None, wrap=False)

 

Locate the intersection of two paths each defined by a start point and an initial bearing.

Parameters:
  • bearing - Initial bearing from this point (compass degrees360).
  • start2 - Start point of second path (LatLon).
  • bearing2 - Initial bearing from start2 (compass degrees360).
  • height - Optional height for intersection point, overriding the mean height (meter).
  • wrap - Wrap and unroll longitudes (bool).
Returns:
Intersection point (LatLon).
Raises:
  • TypeError - Point start2 is not a LatLon.
  • ValueError - Intersection is ambiguous or infinite or the paths are parallel or coincide.

Example:

>>> p = LatLon(51.8853, 0.2545)
>>> s = LatLon(49.0034, 2.5735)
>>> i = p.intersection(108.547, s, 32.435)  # '50.9078°N, 004.5084°E'

isenclosedBy(self, points)

 

Check whether a (convex) polygon encloses this point.

Parameters:
  • points - The polygon points (LatLon[]).
Returns:
True if the polygon encloses this point, False otherwise.
Raises:
  • ValueError - Insufficient number of points or non-convex polygon.
  • TypeError - Some points are not LatLon.

Example:

>>> b = LatLon(45,1), LatLon(45,2), LatLon(46,2), LatLon(46,1)
>>> p = LatLon(45,1, 1.1)
>>> inside = p.isEnclosedBy(b)  # True

midpointTo(self, other, height=None, wrap=False)

 

Find the midpoint between this and an other point.

Parameters:
  • other - The other point (LatLon).
  • height - Optional height for midpoint, overriding the mean height (meter).
  • wrap - Wrap and unroll longitudes (bool).
Returns:
Midpoint (LatLon).
Raises:
  • TypeError - The other point is not LatLon.

Example:

>>> p1 = LatLon(52.205, 0.119)
>>> p2 = LatLon(48.857, 2.351)
>>> m = p1.midpointTo(p2)  # '50.5363°N, 001.2746°E'

nearestOn(self, point1, point2, radius=6371008.77141, **options)

 

Locate the point between two points closest and this point.

Distances are approximated by function equirectangular_, subject to the supplied options.

Parameters:
  • point1 - Start point (LatLon).
  • point2 - End point (LatLon).
  • radius - Optional, mean earth radius (meter).
  • options - Optional keyword arguments for function equirectangular_.
Returns:
Closest point on the arc (LatLon).
Raises:

nearestOn2(self, points, closed=False, radius=6371008.77141, **options)

 

Locate the point on a polygon closest to this point.

Distances are approximated by function equirectangular_, subject to the supplied options.

Parameters:
  • points - The polygon points (LatLon[]).
  • closed - Optionally, close the polygon (bool).
  • radius - Optional, mean earth radius (meter).
  • options - Optional keyword arguments for function equirectangular_.
Returns:
2-Tuple (closest, distance) of the closest point (LatLon) on the polygon and the distance to that point. The distance is the equirectangular_ distance between this and the closest point in meter, same units as radius.
Raises:
  • LimitError - Lat- and/or longitudinal delta exceeds limit, see function equirectangular_.
  • TypeError - Some points are not LatLon.
  • ValueError - Insufficient number of points.

nearestOn3(self, points, closed=False, radius=6371008.77141, **options)

 

Locate the point on a polygon closest to this point.

Distances are approximated by function equirectangular_, subject to the supplied options.

Parameters:
  • points - The polygon points (LatLon[]).
  • closed - Optionally, close the polygon (bool).
  • radius - Optional, mean earth radius (meter).
  • options - Optional keyword arguments for function equirectangular_.
Returns:
3-Tuple (closest, distance, angle) of the closest point (LatLon) on the polygon, the distance and the compass angle to the closest point. The distance is the equirectangular_ distance between this and the closest point in meter, same units as radius. The angle from this to the closest point is in compass degrees360, like function compassAngle.
Raises:
  • LimitError - Lat- and/or longitudinal delta exceeds limit, see function equirectangular_.
  • TypeError - Some points are not LatLon.
  • ValueError - Insufficient number of points.

See Also: Functions compassAngle, equirectangular_ and nearestOn4.

toVector3d(self)

 

Convert this point to a vector normal to earth's surface.

Returns:
Vector representing this point (Vector3d).