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@turf/nearest-point-on-line

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Finds the nearest point on a line to a given point

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import { LineString, MultiLineString, Feature, Point } from 'geojson'; import { Coord, Units } from '@turf/helpers'; /** * Returns the nearest point on a line to a given point. * * If any of the segments in the input line string are antipodal and therefore * have an undefined arc, this function will instead return that the point lies * on the line. * * ⚠️ We have begun the process of migrating to different return properties for * this function. The new properties we recommend using as of v7.4 are: * - lineStringIndex - point was found on the nth LineString of an input MultiLineString. Previously `multiFeatureIndex` * - segmentIndex - point was found on the nth segment of the above LineString. Previously `index` * - totalDistance - distance from the start of the overall MultiLineString. Previously `location` * - lineDistance - distance from the start of the relevant LineString * - segmentDistance - distance from the start of the relevant segment * - pointDistance - distance between found point is from input reference point. Previously `dist` * * multiFeatureIndex, index, location, and dist continue to work as previously * until at least the next major release. * * @function * @param {Geometry|Feature<LineString|MultiLineString>} lines Lines to snap to * @param {Geometry|Feature<Point>|number[]} inputPoint Point to snap from * @param {Object} [options={}] Optional parameters * @param {Units} [options.units='kilometers'] Supports all valid Turf {@link https://turfjs.org/docs/api/types/Units Units} * @returns {Feature<Point>} closest point on the `lines` to the `inputPoint`. The point will have the following properties: `lineStringIndex`: closest point was found on the nth LineString (only relevant if input is MultiLineString), `segmentIndex`: closest point was found on nth line segment of the LineString, `totalDistance`: distance along the line from the absolute start of the MultiLineString, `lineDistance`: distance along the line from the start of the LineString where the closest point was found, `segmentDistance`: distance along the line from the start of the line segment where the closest point was found, `pointDistance`: distance to the input point. * @example * var line = turf.lineString([ * [-77.031669, 38.878605], * [-77.029609, 38.881946], * [-77.020339, 38.884084], * [-77.025661, 38.885821], * [-77.021884, 38.889563], * [-77.019824, 38.892368] * ]); * var inputPoint = turf.point([-77.037076, 38.884017]); * * var snapped = turf.nearestPointOnLine(line, inputPoint, {units: 'miles'}); * * //addToMap * var addToMap = [line, inputPoint, snapped]; * snapped.properties['marker-color'] = '#00f'; */ declare function nearestPointOnLine<G extends LineString | MultiLineString>(lines: Feature<G> | G, inputPoint: Coord, options?: { units?: Units; }): Feature<Point, { lineStringIndex: number; segmentIndex: number; totalDistance: number; lineDistance: number; segmentDistance: number; pointDistance: number; /** @deprecated use `lineStringIndex` instead */ multiFeatureIndex: number; /** @deprecated use `segmentIndex` instead */ index: number; /** @deprecated use `totalDistance` instead */ location: number; /** @deprecated use `pointDistance` instead */ dist: number; [key: string]: any; }>; export { nearestPointOnLine as default, nearestPointOnLine };