Geocalc v0.7.1 Geocalc View Source
Calculate distance, bearing and more between Latitude/Longitude points.
Link to this section Summary
Functions
Calculates bearing. Return radians
Calculates a bounding box around a point with a radius in meters Returns an array with 2 points (list format). The bottom left (southwest) point, and the top-right (northeast) one
Calculates a bounding box for a list of points Returns an array with 2 points (list format). The bottom left (southwest) point, and the top-right (northeast) one
Returns true
if the bounding box contains the given point
Compute distance from the point to great circle defined by start-point and end-point. Return distance in meters
Returns the pair of meridians at which a great circle defined by two points crosses the given latitude. Return longitudes
Converts degrees to radians. Return radians
Finds point between start and end points in direction to end point with given distance (in meters). Finds point from start point with given distance (in meters) and bearing. Return array with latitude and longitude
Calculates distance between 2 points. Return distance in meters
Extend the bounds to contain the given bounds Returns an array with 2 points (list format). The bottom left (southwest) point, and the top-right (northeast) one
Compute the geographic center (aka geographic midpoint, center of gravity) for an array of geocoded objects and/or [lat,lon] arrays (can be mixed). Any objects missing coordinates are ignored. Follows the procedure documented at http://www.geomidpoint.com/calculation.html
Finds intersection point from start points with given bearings. Return array with latitude and longitude. Raise an exception if no intersection point found
Returns true
if the bounding box intersects the given bounds.
Two bounds intersect if they have at least one point in common
Returns maximum latitude reached when travelling on a great circle on given bearing from the point (Clairaut’s formula). Negate the result for the minimum latitude (in the Southern hemisphere). The maximum latitude is independent of longitude; it will be the same for all points on a given latitude. Return radians
Returns true
if the bounding box overlaps the given bounds.
Two bounds overlap if their intersection is an area
Converts radians to degrees. Return degrees
Calculates if a point is within radius of the center of a circle. Return boolean
Link to this section Types
Link to this section Functions
bearing(Geocalc.Point.t(), Geocalc.Point.t()) :: number()
Calculates bearing. Return radians.
Example
iex> berlin = {52.5075419, 13.4251364}
iex> paris = {48.8588589, 2.3475569}
iex> Geocalc.bearing(berlin, paris)
-1.9739245359361486
iex> Geocalc.bearing(paris, berlin)
1.0178267866082613
Example
iex> berlin = %{lat: 52.5075419, lon: 13.4251364}
iex> paris = %{latitude: 48.8588589, longitude: 2.3475569}
iex> Geocalc.bearing(berlin, paris)
-1.9739245359361486
bounding_box(Geocalc.Point.t(), number()) :: list()
Calculates a bounding box around a point with a radius in meters Returns an array with 2 points (list format). The bottom left (southwest) point, and the top-right (northeast) one
Example
iex> berlin = [52.5075419, 13.4251364]
iex> radius = 10_000
iex> Geocalc.bounding_box(berlin, radius)
[[52.417520954378574, 13.277235453275123], [52.59756284562143, 13.573037346724874]]
Calculates a bounding box for a list of points Returns an array with 2 points (list format). The bottom left (southwest) point, and the top-right (northeast) one
Example
iex> berlin = [52.5075419, 13.4251364]
iex> london = [51.5286416, -0.1015987]
iex> paris = [48.8588589, 2.3475569]
iex> Geocalc.bounding_box_for_points([berlin, london, paris])
[[48.8588589, -0.1015987], [52.5075419, 13.4251364]]
contains_point?(list(), Geocalc.Point.t()) :: boolean()
Returns true
if the bounding box contains the given point.
Example
iex> germany = [[47.27, 5.87], [55.1, 15.04]]
iex> berlin = [52.5075419, 13.4251364]
iex> Geocalc.contains_point?(germany, berlin)
true
cross_track_distance_to(Geocalc.Point.t(), Geocalc.Point.t(), Geocalc.Point.t()) :: number()
Compute distance from the point to great circle defined by start-point and end-point. Return distance in meters.
Example
iex> berlin = [52.5075419, 13.4251364]
iex> london = [51.5286416, -0.1015987]
iex> paris = [48.8588589, 2.3475569]
iex> Geocalc.cross_track_distance_to(berlin, london, paris)
-877680.2992295175
crossing_parallels(Geocalc.Point.t(), Geocalc.Point.t(), number()) :: number()
Returns the pair of meridians at which a great circle defined by two points crosses the given latitude. Return longitudes.
Example
iex> berlin = [52.5075419, 13.4251364]
iex> paris = [48.8588589, 2.3475569]
iex> Geocalc.crossing_parallels(berlin, paris, 12.3456)
{:ok, 123.179463369946, -39.81144878508576}
Example
iex> point_1 = %{lat: 0, lng: 0}
iex> point_2 = %{lat: -180, lng: -90}
iex> latitude = 45.0
iex> Geocalc.crossing_parallels(point_1, point_2, latitude)
{:error, "Not found"}
Converts degrees to radians. Return radians.
Example
iex> Geocalc.degrees_to_radians(143.67156782221554)
2.5075419
Example
iex> Geocalc.degrees_to_radians(-10.735322818996854)
-0.18736672945597435
destination_point(Geocalc.Point.t(), point_or_bearing(), number()) :: tuple()
Finds point between start and end points in direction to end point with given distance (in meters). Finds point from start point with given distance (in meters) and bearing. Return array with latitude and longitude.
Example
iex> berlin = [52.5075419, 13.4251364]
iex> paris = [48.8588589, 2.3475569]
iex> bearing = Geocalc.bearing(berlin, paris)
iex> distance = 400_000
iex> Geocalc.destination_point(berlin, bearing, distance)
{:ok, [50.97658022467569, 8.165929595956982]}
Example
iex> zero_point = {0.0, 0.0}
iex> equator_degrees = 90.0
iex> equator_bearing = Geocalc.degrees_to_radians(equator_degrees)
iex> distance = 1_000_000
iex> Geocalc.destination_point(zero_point, equator_bearing, distance)
{:ok, [5.484172965344896e-16, 8.993216059187306]}
Example
iex> berlin = %{lat: 52.5075419, lon: 13.4251364}
iex> bearing = -1.9739245359361486
iex> distance = 100_000
iex> Geocalc.destination_point(berlin, bearing, distance)
{:ok, [52.147030316318904, 12.076990111001148]}
Example
iex> berlin = [52.5075419, 13.4251364]
iex> paris = [48.8588589, 2.3475569]
iex> distance = 250_000
iex> Geocalc.destination_point(berlin, paris, distance)
{:ok, [51.578054644172525, 10.096282782248409]}
distance_between(Geocalc.Point.t(), Geocalc.Point.t()) :: number()
Calculates distance between 2 points. Return distance in meters.
Example
iex> berlin = [52.5075419, 13.4251364]
iex> paris = [48.8588589, 2.3475569]
iex> Geocalc.distance_between(berlin, paris)
878327.4291149472
iex> Geocalc.distance_between(paris, berlin)
878327.4291149472
Example
iex> berlin = %{lat: 52.5075419, lon: 13.4251364}
iex> london = %{lat: 51.5286416, lng: -0.1015987}
iex> paris = %{latitude: 48.8588589, longitude: 2.3475569}
iex> Geocalc.distance_between(berlin, paris)
878327.4291149472
iex> Geocalc.distance_between(paris, london)
344229.88946533133
Extend the bounds to contain the given bounds Returns an array with 2 points (list format). The bottom left (southwest) point, and the top-right (northeast) one
Example
iex> berlin = [52.5075419, 13.4251364]
iex> london = [51.5286416, -0.1015987]
iex> Geocalc.extend_bounding_box([berlin, berlin], [london, london])
[[51.5286416, -0.1015987], [52.5075419, 13.4251364]]
geographic_center(list()) :: Geocalc.Point.t()
Compute the geographic center (aka geographic midpoint, center of gravity) for an array of geocoded objects and/or [lat,lon] arrays (can be mixed). Any objects missing coordinates are ignored. Follows the procedure documented at http://www.geomidpoint.com/calculation.html.
Example
iex> point_1 = [0, 0]
iex> point_2 = [0, 3]
iex> Geocalc.geographic_center([point_1, point_2])
[0.0, 1.5]
intersection_point( Geocalc.Point.t(), point_or_bearing(), Geocalc.Point.t(), point_or_bearing() ) :: tuple()
Finds intersection point from start points with given bearings. Return array with latitude and longitude. Raise an exception if no intersection point found.
Example
iex> berlin = [52.5075419, 13.4251364]
iex> berlin_bearing = -2.102
iex> london = [51.5286416, -0.1015987]
iex> london_bearing = 1.502
iex> Geocalc.intersection_point(berlin, berlin_bearing, london, london_bearing)
{:ok, [51.49271112601574, 10.735322818996854]}
Example
iex> berlin = {52.5075419, 13.4251364}
iex> london = {51.5286416, -0.1015987}
iex> paris = {48.8588589, 2.3475569}
iex> Geocalc.intersection_point(berlin, london, paris, london)
{:ok, [51.5286416, -0.10159869999999019]}
Example
iex> berlin = %{lat: 52.5075419, lng: 13.4251364}
iex> bearing = Geocalc.degrees_to_radians(90.0)
iex> Geocalc.intersection_point(berlin, bearing, berlin, bearing)
{:error, "No intersection point found"}
Returns true
if the bounding box intersects the given bounds.
Two bounds intersect if they have at least one point in common.
Example
iex> germany = [[47.27, 5.87], [55.1, 15.04]]
iex> poland = [[49.0, 14.12], [55.03, 24.15]]
iex> Geocalc.intersects_bounding_box?(germany, poland)
true
max_latitude(Geocalc.Point.t(), number()) :: number()
Returns maximum latitude reached when travelling on a great circle on given bearing from the point (Clairaut’s formula). Negate the result for the minimum latitude (in the Southern hemisphere). The maximum latitude is independent of longitude; it will be the same for all points on a given latitude. Return radians.
Example
iex> berlin = [52.5075419, 13.4251364]
iex> paris = [48.8588589, 2.3475569]
iex> bearing = Geocalc.bearing(berlin, paris)
iex> Geocalc.max_latitude(berlin, bearing)
55.953467429882835
Returns true
if the bounding box overlaps the given bounds.
Two bounds overlap if their intersection is an area.
Example
iex> germany = [[47.27, 5.87], [55.1, 15.04]]
iex> berlin_suburbs = [[52.338261, 13.08835], [52.67551, 13.76116]]
iex> Geocalc.overlaps_bounding_box?(germany, berlin_suburbs)
true
Converts radians to degrees. Return degrees.
Example
iex> Geocalc.radians_to_degrees(2.5075419)
143.67156782221554
Example
iex> Geocalc.radians_to_degrees(-0.1015987)
-5.821176714015797
within?(number(), Geocalc.Point.t(), Geocalc.Point.t()) :: boolean()
Calculates if a point is within radius of the center of a circle. Return boolean.
Example
iex> berlin = [52.5075419, 13.4251364]
iex> paris = [48.8588589, 2.3475569]
iex> Geocalc.within?(10, paris, berlin)
false
iex> Geocalc.within?(10, berlin, paris)
false
Example
iex> san_juan = %{lat: 18.4655, lon: 66.1057}
iex> puerto_rico = %{lat: 18.2208, lng: 66.5901}
iex> Geocalc.within?(170_000, puerto_rico, san_juan)
true