getRadarStationClosest(observationStations: {}, lat: string, long: string): string {
const radarStations = <any> observationStations;
let closestStation = '';
let firstTime = true;
let minDistance = 0;
const x1: number = parseFloat(long);
const y1: number = parseFloat(lat);
radarStations.forEach((element) => {
// when calculating distance use the distance formula
// sqrt of (x2-x1)^2 + (y2-y1)^2
// long = x
// lat = y
const x2: number = parseFloat(element['geometry']['coordinates'][0]);
const y2: number = parseFloat(element['geometry']['coordinates'][1]);
const xSquared: number = (x2 - x1) * (x2 - x1);
const ySquared: number = (y2 - y1) * (y2 - y1);
const distance = Math.sqrt(xSquared + ySquared);
if (firstTime) {
firstTime = false;
minDistance = distance;
closestStation = element['id'];
} else {
if (distance < minDistance) {
minDistance = distance;
closestStation = element['id'];
}
}
});
return closestStation;
}
When I was working on my Angular weather app I recently had to use the distance formula from Algebra and wanted to share it here.
The reason I was using it was to find the nearest radar station given coordinates (latitude and longitude). I was using an endpoint that gave me a set of radar stations for an area, and I needed to identify the closest one.
After some testing, I found out that the NOAA APIs that I was using actually provided more accurate readings with a different endpoint that didn’t require me to do this math.
I thought using the distance formula was still cool, and just wanted to post it here for future reference. Also checkout the following video on how to use the distance formula.
