36 lines
983 B
TypeScript
36 lines
983 B
TypeScript
//This function takes in latitude and longitude of two location and returns the distance between them as the crow flies (in km)
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function CoordDistance(lat1: number, lon1: number, lat2: number, lon2: number) {
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const R = 6371; // km
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const dLat = toRad(lat2 - lat1);
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const dLon = toRad(lon2 - lon1);
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const lat1_calc = toRad(lat1);
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const lat2_calc = toRad(lat2);
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const a =
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Math.sin(dLat / 2) * Math.sin(dLat / 2) +
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Math.sin(dLon / 2) *
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Math.sin(dLon / 2) *
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Math.cos(lat1_calc) *
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Math.cos(lat2_calc);
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const c = 2 * Math.atan2(Math.sqrt(a), Math.sqrt(1 - a));
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const d = R * c;
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return d;
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}
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// Converts numeric degrees to radians
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function toRad(value: number) {
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return (value * Math.PI) / 180;
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}
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export function handleDistanceCoord(
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lat1: number,
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lon1: number,
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lat2: number,
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lon2: number,
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) {
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const distance = CoordDistance(lat1, lon1, lat2, lon2);
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if (distance < 1) {
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return `~${Math.round(distance * 1000)} m`;
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}
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return `~${Math.round(distance)} km`;
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}
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