Specs

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

Specs

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]]

Specs

bounding_box_for_points(list()) :: list()

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]]

Specs

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

Specs

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

Specs

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"}

Specs

degrees_to_radians(number()) :: number()

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

Specs

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]}

Specs

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

Specs

extend_bounding_box(list(), list()) :: list()

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]]

Specs

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]

Specs

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, -0.10159869999998701]}

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)
{:ok, [52.5075419, 13.4251364]}

Example

iex> berlin_1 = %{lat: 52.5075419, lng: 13.4251364}
iex> berlin_2 = %{lat: 52.5075419, lng: 13.57}
iex> bearing = Geocalc.degrees_to_radians(90.0)
iex> Geocalc.intersection_point(berlin_1, bearing, berlin_2, bearing)
{:error, "No intersection point found"}

Specs

intersects_bounding_box?(list(), list()) :: boolean()

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

Specs

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

Specs

overlaps_bounding_box?(list(), list()) :: boolean()

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

Specs

radians_to_degrees(number()) :: number()

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

Specs

within?([Geocalc.Point.t()], Geocalc.Point.t()) :: boolean()

Calculates if a point is within a polygon. Return boolean.

Example

iex> point = [14.952242, 60.1696017]
iex> poly = [[24.950899, 60.169158], [24.953492, 60.169158], [24.953510, 60.170104], [24.950958, 60.169990]]
iex> Geocalc.within?(poly, point)
false

Example

iex> point = [24.952242, 60.1696017]
iex> poly = [[24.950899, 60.169158], [24.953492, 60.169158], [24.953510, 60.170104], [24.950958, 60.169990]]
iex> Geocalc.within?(poly, point)
true

Example

iex> point = [24.976567, 60.1612500]
iex> poly = [[24.950899, 60.169158], [24.953492, 60.169158], [24.953510, 60.170104], [24.950958, 60.169990]]
iex> Geocalc.within?(poly, point)
false

Specs

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