The formula you used, seems to be the arccosine instead of the haversine formula. The haversine formula is indeed more appropriate to calculate the distance on a sphere, because it is less prone to rounding errors. /** * Calculates the great-circle distance between two points, with * the Haversine formula. * @param float $latitudeFrom Latitude … Read more
you can use this great solution (c) @derricw (don’t forget to upvote it ;-): # vectorized haversine function def haversine(lat1, lon1, lat2, lon2, to_radians=True, earth_radius=6371): “”” slightly modified version: of http://stackoverflow.com/a/29546836/2901002 Calculate the great circle distance between two points on the earth (specified in decimal degrees or in radians) All (lat, lon) coordinates must have … Read more
Your code seems fine to me. Nothing wrong with the calculous. You don’t specify how far off your results are, but you might try tweaking your radian/degrees converters to this: double DegreesToRadians(double degrees) {return degrees * M_PI / 180.0;}; double RadiansToDegrees(double radians) {return radians * 180.0/M_PI;}; If you are getting negative bearings, add 2*M_PI to … Read more
This code is working: Number.prototype.toRad = function() { return this * Math.PI / 180; } var lat2 = 42.741; var lon2 = -71.3161; var lat1 = 42.806911; var lon1 = -71.290611; var R = 6371; // km //has a problem with the .toRad() method below. var x1 = lat2-lat1; var dLat = x1.toRad(); var x2 … Read more
I can’t confirm if the calculations are correct but the following worked: In [11]: from numpy import cos, sin, arcsin, sqrt from math import radians def haversine(row): lon1 = -56.7213600 lat1 = 37.2175900 lon2 = row[‘LON’] lat2 = row[‘LAT’] lon1, lat1, lon2, lat2 = map(radians, [lon1, lat1, lon2, lat2]) dlon = lon2 – lon1 dlat … Read more
Not long ago I wrote an example of the haversine formula, and published it on my website: /** * Calculates the great-circle distance between two points, with * the Haversine formula. * @param float $latitudeFrom Latitude of start point in [deg decimal] * @param float $longitudeFrom Longitude of start point in [deg decimal] * @param … Read more
Here is a vectorized numpy version of the same function: import numpy as np def haversine_np(lon1, lat1, lon2, lat2): “”” Calculate the great circle distance between two points on the earth (specified in decimal degrees) All args must be of equal length. “”” lon1, lat1, lon2, lat2 = map(np.radians, [lon1, lat1, lon2, lat2]) dlon = … Read more
Here’s a Python version: from math import radians, cos, sin, asin, sqrt def haversine(lon1, lat1, lon2, lat2): “”” Calculate the great circle distance in kilometers between two points on the earth (specified in decimal degrees) “”” # convert decimal degrees to radians lon1, lat1, lon2, lat2 = map(radians, [lon1, lat1, lon2, lat2]) # haversine formula … Read more
Calculate distance between two latitude-longitude points? (Haversine formula)