27 lines
1.0 KiB
JavaScript
Executable File
27 lines
1.0 KiB
JavaScript
Executable File
import distance from "@turf/distance";
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import { segmentReduce } from "@turf/meta";
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/**
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* Takes a {@link GeoJSON} and measures its length in the specified units, {@link (Multi)Point}'s distance are ignored.
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*
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* @name length
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* @param {Feature<LineString|MultiLineString>} geojson GeoJSON to measure
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* @param {Object} [options={}] Optional parameters
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* @param {string} [options.units=kilometers] can be degrees, radians, miles, or kilometers
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* @returns {number} length of GeoJSON
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* @example
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* var line = turf.lineString([[115, -32], [131, -22], [143, -25], [150, -34]]);
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* var length = turf.length(line, {units: 'miles'});
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*
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* //addToMap
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* var addToMap = [line];
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* line.properties.distance = length;
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*/
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export default function length(geojson, options) {
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if (options === void 0) { options = {}; }
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// Calculate distance from 2-vertex line segments
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return segmentReduce(geojson, function (previousValue, segment) {
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var coords = segment.geometry.coordinates;
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return previousValue + distance(coords[0], coords[1], options);
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}, 0);
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}
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