Measurement¶
along¶
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turf.along(line, dist, options=None)[source]¶ Takes a LineString and returns a Point at a specified distance along the line
- Parameters
line – input LineString
dist – distance along the line
options – optional parameters [options[“units”]=”kilometers”] can be degrees, radians, miles, or kilometers
- Returns
Point dist units along the line
area¶
bbox¶
bbox-polygon¶
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turf.bbox_polygon(bbox, options=None)[source]¶ Takes a bounding box and returns an equivalent Polygon feature.
- Parameters
bbox – bounding box extent in [minX, minY, maxX, maxY] order
options – optional parameters [options[“properties”]={}] Translate GeoJSON Properties to Point [options[“id”]={}] Translate GeoJSON Id to Point
- Returns
a Polygon representation of the bounding box
bearing¶
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turf.bearing(start, end, options=None)[source]¶ Takes two points and finds the geographic bearing between them, i.e. the angle measured in degrees from the north line (0 degrees)
- Parameters
start – starting point [lng, lat] or Point feature
end – ending point [lng, lat] or Point feature
options – dictionary with options: [options[“final”]] - calculates the final bearing if true
- Returns
bearing in decimal degrees, between -180 and 180 (positive clockwise)
center¶
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turf.center(features, options=None)[source]¶ Takes a Feature or FeatureCollection and returns the absolute center point of all features.
- Parameters
features – features or collection of features
options – optional parameters [options[“properties”]={}] Translate GeoJSON Properties to Point [options[“bbox”]={}] Translate GeoJSON BBox to Point [options[“id”]={}] Translate GeoJSON Id to Point
- Returns
a Point feature at the absolute center point of all input features
centroid¶
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turf.centroid(features, options=None)[source]¶ Takes one or more features and calculates the centroid using the mean of all vertices. This lessens the effect of small islands and artifacts when calculating the centroid of a set of polygons.
- Parameters
features – GeoJSON features to be centered
options – optional parameters [options[“properties”]={}] Translate GeoJSON Properties to Point
- Returns
a Point feature corresponding to the centroid of the input features
destination¶
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turf.destination(origin, distance, bearing, options=None)[source]¶ Takes a Point and calculates the location of a destination point given a distance in degrees, radians, miles, or kilometers; and bearing in degrees. This uses the [Haversine formula](http://en.wikipedia.org/wiki/Haversine_formula) to account for global curvature.
- Parameters
origin – starting point
distance – distance from the origin point
bearing – bearing ranging from -180 to 180
options – optional parameters [options[“units”]=’kilometers’] miles, kilometers, degrees, or radians [options[“properties”]={}] Translate properties to Point
- Returns
destination GeoJSON Point feature
distance¶
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turf.distance(start, end, options=None)[source]¶ Calculates the distance between two Points in degrees, radians, miles, or kilometers. This uses the [Haversine formula](http://en.wikipedia.org/wiki/Haversine_formula) to account for global curvature.
- Parameters
start – starting point [lng, lat] or Point feature
end – ending point [lng, lat] or Point feature
options – dictionary with units as an attribute. Can be degrees, radians, miles, or kilometers
- Returns
distance between the 2 points
envelope¶
length¶
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turf.length(features, options=None)[source]¶ Calculates the total length of the input Feature / FeatureCollection in the specified units.
- Parameters
features – a Feature / FeatureCollection of types LineString, MultiLineString, Polygon or MultiPolygon
options – optional parameters [options[“units”]=kilometers] can be degrees, radians, miles, or kilometers
- Returns
the measured distance
midpoint¶
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turf.midpoint(point1, point2)[source]¶ Takes two point features and returns a point midway between them. The midpoint is calculated geodesically, meaning the curvature of the earth is taken into account.
- Parameters
point1 – first point
point2 – second point
- Returns
a point midway between point 1 and point 2
nearest-point¶
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turf.nearest_point(target: Union[Sequence, Dict, turf.helpers._features.Feature], features: GeoJson) → turf.helpers._features.Point[source]¶ Calculates the closest reference point from a feature collection towards a target point This calculation is geodesic.
- Parameters
target – targetPoint the reference point
features – points against input point set
- Returns
the closest point in the features set to the reference point
point-on-feature¶
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turf.point_on_feature(features: GeoJSON) → turf.helpers._features.Point[source]¶ Takes a Feature or FeatureCollection and returns a {Point} guaranteed to be on the surface of the feature.
Given a {Polygon}, the point will be in the area of the polygon Given a {LineString}, the point will be along the string Given a {Point}, the point will the same as the input
- Parameters
features – any GeoJSON feature or feature collection
- Returns
Point GeoJSON Feature on the surface of input
point-to-line-distance¶
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turf.point_to_line_distance(point: Union[Sequence, Dict, turf.helpers._features.Feature], line: Union[Sequence, Dict, turf.helpers._features.Feature], options: Dict = None) → float[source]¶ Returns the minimum distance between a {Point} and a {LineString}, being the distance from a line the minimum distance between the point and any segment of the LineString
http://geomalgorithms.com/a02-_lines.html
- Parameters
point – Point GeoJSON Feature or Geometry
line – LineString GeoJSON Feature or Geometry
options – Optional parameters [options[“units”]]: any supported unit (e.g. degrees, radians, miles…) [options[“method”]]: geodesic or ‘planar for distance calculation
- Returns
distance between point and line
polygon-tangents¶
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turf.polygon_tangents(start_point: PointFeature, polygon: PolygonFeature) → turf.helpers._features.FeatureCollection[source]¶ Finds the tangents of a {Polygon or(MultiPolygon} from a {Point}.
more: http://geomalgorithms.com/a15-_tangents.html
- Parameters
point – point [lng, lat] or Point feature to calculate the tangent points from
polygon – polygon to get tangents from
- Returns
Feature Collection containing the two tangent points
rhumb-bearing¶
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turf.rhumb_bearing(origin: Union[Sequence, Dict, turf.helpers._features.Feature], destination: Union[Sequence, Dict, turf.helpers._features.Feature], options: Dict = None) → float[source]¶ Takes two {Point|points} and finds the bearing angle between them along a Rhumb line * i.e. the angle measured in degrees start the north line (0 degrees)
https://en.wikipedia.org/wiki/Rhumb_line
- Parameters
start – starting point [lng, lat] or Point feature
end – ending point [lng, lat] or Point feature
options – Optional parameters [options[“final”]]: Calculates the final bearing if True
- Returns
bearing from north in decimal degrees
rhumb-destination¶
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turf.rhumb_destination(features: Dict, options: Dict = None) → turf.helpers._features.Point[source]¶ Returns the destination {Point} having travelled the given distance along a Rhumb line from the origin Point with the (varant) given bearing.
# https://en.wikipedia.org/wiki/Rhumb_line
- Parameters
features – any GeoJSON feature or feature collection
properties – specification to calculate the rhumb line [options[“distance”]=100] distance from the starting point [options[“bearing”]=180] varant bearing angle ranging from -180 to 180 degrees from north [options[“units”]=kilometers] units: specifies distance (can be degrees, radians, miles, or kilometers)
options – optional parameters also be part of features[“properties”] [options[“units”]={}] can be degrees, radians, miles, or kilometers [options[“properties”]={}] Translate GeoJSON Properties to Point [options[“id”]={}] Translate GeoJSON Id to Point
- Returns
a FeatureDestination point.
rhumb-distance¶
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turf.rhumb_distance(origin, destination, options: Dict = None) → float[source]¶ Calculates the rhumb distance between two Points. Units are defined in helpers._units
# https://en.wikipedia.org/wiki/Rhumb_line
- Parameters
start – starting point [lng, lat] or Point feature
end – ending point [lng, lat] or Point feature
options – dictionary with units as an attribute. Units are defined in helpers._units
- Returns
distance between the 2 points
square¶
great-circle¶
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turf.great_circle(start, end, options=None)[source]¶ Returns the great circle route as LineString
- Parameters
start – source point feature
end – destination point feature
options – Optional parameters [options[“properties”]={}] line feature properties [options.npoints=100] number of points
- Returns
great circle line feature