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29 lines
959 B
JavaScript
29 lines
959 B
JavaScript
export const middleCoord = (l1, l2) => ({
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lat: (l2.lat + ((l1.lat - l2.lat) / 2)),
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lng: (l2.lng + ((l1.lng - l2.lng) / 2))
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});
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export const deg2rad = deg => deg * Math.PI / 180;
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export const findDistance = (t1, n1, t2, n2) => {
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// convert coordinates to radians
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const lat1 = deg2rad(t1);
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const lon1 = deg2rad(n1);
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const lat2 = deg2rad(t2);
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const lon2 = deg2rad(n2);
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// find the differences between the coordinates
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const dlat = lat2 - lat1;
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const dlon = lon2 - lon1;
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// here's the heavy lifting
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const a = (Math.sin(dlat / 2) ** 2) +
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(Math.cos(lat1) * Math.cos(lat2) * (Math.sin(dlon / 2) ** 2));
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const c = 2 * Math.atan2(Math.sqrt(a), Math.sqrt(1 - a)); // great circle distance in radians
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// const dm = c * 3961; // great circle distance in miles
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const dk = c * 6373; // great circle distance in km
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// round the results down to the nearest 1/1000
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// const mi = round(dm);
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return (Math.round(dk * 1000) / 1000);
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};
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