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March 7, 2023 16:51
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Add jitter to latitude/longitude
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// | |
// Make a few assumptions and add noise to latitude/longitude position | |
// Ex, console.log(jitter(-26.4853429150483, -49.072945734375, 5)); | |
// | |
var rad_Earth = 6378.16; | |
var one_degree = (2 * Math.PI * rad_Earth) / 360; | |
var one_km = 1 / one_degree; | |
function randomInRange(from, to, fixed) { | |
fixed = fixed || 10; | |
return (Math.random() * (to - from) + from).toFixed(fixed) * 1; | |
} | |
function jitter(lat, lng, kms, fixed) { | |
return { | |
lat : randomInRange( | |
lat - (kms * one_km), | |
lat + (kms * one_km), | |
fixed | |
), | |
lng : randomInRange( | |
lng - (kms * one_km), | |
lng + (kms * one_km), | |
fixed | |
) | |
}; | |
} |
Thx for an example!
<?php
use MStaack\LaravelPostgis\Geometries\Point;
/**
* Данный класс добавляет шум в координаты
*/
class Jitter
{
const ONE_KM = 0.008983120447446;
private float $variation;
private Point $point;
private int $precision;
/**
* @param Point $point Координата
* @param int $meters Возможное отклонение координат относительно стартовой позиции в метрах
* @param int $precision Точность исходящей координаты (кол-во знаков после запятой)
*/
public function __construct(Point $point, int $meters = 10, int $precision = 10)
{
$this->variation = $meters / 1000 * static::ONE_KM;
$this->point = $point;
$this->precision = $precision;
}
/**
* Создание новой точки с рандомным отклонением
*
* @return Point
*/
public function make(): Point
{
return new Point(
$this->randomize($this->point->getLat()),
$this->randomize($this->point->getLng())
);
}
protected function randomize(float $coordinate): float
{
$from = $coordinate - $this->variation;
$to = $coordinate + $this->variation;
return round(
(mt_rand() / (mt_getrandmax() + 1)) * ($to - $from) + $from,
$this->precision
);
}
}
Thank you! used as is in a mapbox map and worked as charm
🍻
Great!
For the sake of Typescript
Instead of
return (Math.random() * (to - from) + from).toFixed(fixed) * 1;
maybe
return parseFloat((Math.random() * (to - from) + from).toFixed(fixed));
?
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could you please add some description of your method sir?, and how can rut it using google map