The Haversine calculator computes the distance between two points on a spherical model of the Earth along a great circle arc. This way you can test, if the two places are within a certain radius (a circle instead of the box). Python function to calculate distance using haversine formula in pandas. Here is a very detailed description of Geo Distance Search with MySQL a solution based on implementation of Haversine Formula to mysql. 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. from geopy. Python Solution. # Haversine formula example in Python. Outer join to city Geo coordinates with city cluster coordinates to get all possible combinations. . Name the file new. This is accomplished using the Haversine formula. Haversine Formula has its own law that is all equations are used based on the shape of a spherical earth by eliminating the factor that the earth is slightly elliptical (ellipsoidal factor). 249672) then I get 232. lat2: The latitude of the second. You can use the haversine formula to calculate the great-circle distance between two points on a sphere given their longitudes and latitudes. I have the columns of Latitude and Longitude of city like shown below : City Latitude Longitude 1) Vauxhall Food & Beer Garden -0. spatial. For this system, we have developed a python script, an. The first is that while the ArcGIS Map has an option for distance radius, it only allows a maximum of 100 miles / 161 kilometers. haversine is a Python library that calculates the distance between two points on Earth using their latitude and longitude in various units. - lat1 and lat2 are the latitudes of the two points. 0. ). Remember that this works on 4 columns csv file with multiple coordinates value. The Haversine formula is perhaps the first equation to consider when understanding how to calculate distances on a sphere. . Python implementation. The Canberra distance between two points u and v is. Scipy Pairwise() We have created a dist object with haversine metrics above and now we will use pairwise() function to calculate the haversine distance between each of the element with each other in this array. Args: lat1: The latitude of the first point in degrees. We can now define the formula of haversine for calculating the distance between two points in the spherical coordinate system. Like this: First 3 rows of first dataframe. We can now define the formula of haversine for calculating the distance between two points in the spherical coordinate. This allows dynamic analysis of the customers, flows, weight, revenue, and any other value within the selected distance. Related questions. I was reading Haversine formula on wikipedia and at the end of article its state that "More accurate methods that consider the Earth's ellipticity are given by Vincenty's formula and the other formulas in the geographical distance article. The code below is a direct implementation of the equations in the Wikipedia article. Calculate Distance using Haversine Formula in PythonMengukur jarak berdasarkan koordinat GPS, latitude, longitude, menggunakan Haversine formula. PYTHON : Haversine Formula in Python (Bearing and Distance between two GPS points) [ Gift : Animated Search Engine : Formula . bounds [1] lon2, lat2 = point2. geometry import Point, shape from pyproj import Proj, transform from geopy. The haversine formula is an equation important in navigation, giving great-circle distances between two points on a sphere from their longitudes and latitudes. Django VS Flask: A Detailed Look at Python Web Frameworks Top Mistakes that Python Programmers Make; Haversine Formula for Calculating GPS Distances; 3 Effective Methods for Applying Gaussian Filters to Images; Python Equivalent of Histfit and Fitdist; Python Equivalent to Matlab’s Bwdist: A Comprehensive Guide; What Is Carry. 788827,. Python function to calculate distance using. ¶. To use the haversine. -120. This is a special case of a general formula in spherical trigonometry which is related to the sides and angles of a spherical하버사인 공식 (Haversine Formula) 이런 경우 두 위경도 좌표 사이의 거리를 구할 때 사용하는 것이 하버사인 공식입니다. 043200. Big or small, always start with a plan, use. It will help us to predict the nearest store for delivery, pick up orders. It is applied to waveforms, which can be seen as high-dimensional vector. Have a great day. haversine((41. The Haversine Formula is defined like this: Haversine Formula. 817923,-73. The word "Haversine" comes from the function:. However, when i reduce the data to a minimal size, the Haversine formula works. 34. - Δlon is the difference between the longitudes. 000015″ of bearing; the Haversine formulas are accurate to approximately 0. TL;DR - By making a few geometric assumptions, the Haversine formula provides an exceptionally simple way of calculating the distance between two. ( rasterio, geopandas) Collect all water points to one multipoint object. I'm calculating the distance between 33. pip install haversine. apply passes the row object (or column with axis=0) to the target function. Image courtesy USGS. You would provide your function as an argument to np. To match that in ArcGIS, you'd have to have the data's CRS use the same sphere model. 565253 95. ". In this article, we explore four methods to calculate the distance between two points using latitude and longitude in Python. The haversine formula determines the great-circle distance between two points on a sphere given their longitudes and latitudes. It is a special case of a more general formula in spherical trigonometry, the law of haversines, relating the sides and angles of spherical "triangles". This formula is widely used in geographic. py. Algorithm. neighbors import DistanceMetric def sklearn_haversine (lat, lon): haversine = DistanceMetric. INSTRUCTIONS: Enter the following: (Lat1) Latitude of. The haversine formula is an equation important in navigation, giving great-circle distances between two points on a sphere from their longitudes and latitudes. Haversine Formula in Python (Bearing and Distance between two GPS points) Find direction from A to B (bearing): Determine compass direction from one lat/lon to the other. Formula ini memperhitungkan bahwa permukaan bumi tidak datar, melainkan melengkung seperti bola. py) values between radians and degrees as the default option for python's math package is radians. Vectorised Haversine formula with a pandas dataframe. The user may want to assume a slightly different earth radius, so this can be provided as input. sin (dlat/2. There are several related functions, most notably the coversine and haversine. Sep 7, 2020. 698661, 5. Let’s have a look at a non-vectorized implementation in pure Python first:I have a set of lat/long coordinates and need to offset the value to the "left" by < 10 meters. 1. 427724 then I get 233 km. 1. Calculate the distance between two given latitude and longitude points using the Haversine formula. The popularly published haversine formula, whether in python or another language, because it is going to be most likely using the IEEE 754 floating point spec on most all intel and intel-like systems today, and ARM processors, powerPC, etc, it is going to also be susceptible to rare but real and repeatable exception errors very near or at 180. 9425/N 118. py This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. NumPy / Python. Cite. Important in navigation, it is a special case of a more general formula in spherical trigonometry, the law of haversines, that relates the sides and angles of spherical triangles. 36056 - the long result I'm hoping for. I have two dataframes, df1 and df2, each containing latitude and longitude data. 88465, 145. 2 Answers. ) There is no such thing as a global projection that yields highly accurate distances everywhere. The first distance of each point is assumed to be the latitude, while the second is the longitude. def mean (data): n = len (data) mean = sum (data) / n return mean. Vectorised Haversine formula with a pandas dataframe. Try this solution: 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. google geocoding and haversine distance calculation in R. 0. 4. Written in C, wrapped in Python. There is also a haversine function which you can pass to cdist. This function will calculate the mean. 8915,. The distance between two lat/lon points can be calculate by Haversine formula like Calculate distance between two latitude-longitude points? (Haversine formula) python; scikit-learn; geolocation; interpolation;Three little php and JS snippets that do the same, calculate the distance between two points on earth in kilometers, miles and nautic miles. Find destination coordinates given starting coordinates, bearing, and distance. Calculate the geographical distance (in kilometers or miles) between 2 points with extreme accuracy. dice (u, v [, w]) Compute the Dice dissimilarity between two boolean 1-D arrays. DataFrame (haversine_distances (np. Haversine distance is the angular distance between two points on the surface of a sphere. In the above-mentioned syntax for calculating the limit in Python. I have tried two approaches, but performance becomes an issue with larger datasets. metrics. The distance calculations appear to be spot-on. 5 mm distance or 0. Then, we will import the haversine library using the import function of the python. Why is this Python Haversine formula producing incorrect answers? 1. Inaccurate Result from Haversine's Bearing Calculation. GPS - Is the haversine formula accurate for distance between two nearby gps points? 3. The haversine formula determines the great-circle distance between two points on a sphere given their longitudes and latitudes. 5 mm distance or 0. The answer should be 233 km, but my approach is giving ~8000 km. Nearest Neighbors Classification¶. distance calculator using Haversine formula to determine distance between an origin and an array of coordinates . The great-circle distance, orthodromic distance, or spherical distance is the distance along a great circle . So we have to use a special type of formula known as Haversine Distance. GeocoderTimedOut exception. import pandas as pd import numpy as np input_file = "input. The distance between two points in Euclidean space is the. There are a couple of library functions that can help you with this: cdist from scipy can be used to generate a distance matrix using whichever distance metric you like. haversine - finds spherical distance in km between two sets of (lat, lon) coordinates; bearing - finds bearing in degrees between two sets of (lat, lon). import numpy as np from sklearn. Implement a great-circle. So, don't name your function dist, name it haversine_distance. 436554) and KANSAS, USA (Latitude : 38. 123684 51. Share. 69. SharePoint - How to Patch the 6 most complex data typesAs pointed out in comments, is there a generalization of the Haversine formula? geometry; Share. WIP : Using Haversine formula and folium maps in python, we aim to create a system to track citizens and send them alerts in a pandemic scenario, like the COVID-19. lon1: The longitude of the first point in degrees. In [1]: import pandas as pd import numpy as np from. 📐 Compute distance between sequences. Updated for V1. Important in navigation, it is a special case of a more general formula in spherical trigonometry, the law of haversines, that relates the sides and angles of spherical triangles. sin(d_lat / 2) ** 2 + math. The formula written above with squares of sines can be written more concisely with the haversine: havθ = hav(φ1 − φ2) + cosφ1cosφ2hav(λ1 − λ2) Apart from conciseness, there is another advantage. Getting distance from longitude and latitude using Haversine's distance formula 3 Trying to get distance using longitude and latitude, but keep running to an error: 'Series' object has no attribute 'radians'Here's the code I've got in Python. db = DBSCAN (eps=2/6371. The following psuedocode should do the trick:It would be far easier for you to switch to a location aware database likes postgresql (with postgis extension) or mysql 5. d = 15 #Distance in km #lat2 52. 1. Finalmente, a função haversine hav (Θ), aplicada acima para ambos o ângulo central Θ e a diferenças. 335142 5. It translated to PQ/PBI and worked! The other thing I needed was to convert the latitude and longitude values I had by 1,000,000 and -1,000,000. We use cookies for various purposes including analytics. Here is the implementation of the Haversine formula in. The haversine formula is an equation important in navigation, giving great-circle distances between two points on a sphere from their longitudes and latitudes. Credit to my son, Bill Karr,. 5:1-5 John is weeping much because only Jesus is worthy to open the book. It is one of the most immersive fields to work in. Note that the concatenation of lat and lon is only. I am trying to find the nearest underground station given a point using the Haversine formula implementation in Python, but I get a KeyError, which i think means that the key is not in the dictionaries. Limits in calculus are used to define continuity, derivatives, and integrals of a function sequence. mkolar. The Haversine formula assumes the inputs are in the order (latitude, longitude) and in radians. 0. Geospatial Machine Learning is also a trending field that involves building and training. 427724, 72. Keep in mind that the Haversine formula assumes a perfect sphere, which is an approximation of the Earth’s shape. code function name dist doesn't tell us, users/readers of your code, that you're using the Haversine Distance. Calculate the geographical distance (in kilometers or miles) between 2 points with extreme accuracy. Compute the distance matrix from a vector array X and optional Y. Haversine formula in Python (bearing and distance between two GPS points) 3. cdist (all_points, all_points, get_distance) As a bonus you can convert the distance matrix to a data frame if you wish to add the index to each point: I am new to Python. 82120, 144. I once wrote a python version of this answer. all_points = df [ [latitude_column, longitude_column]]. (Code Reference: Haversine Formula in Python) from math import radians, cos, sin, asin, sqrt def haversine(lon1, lat1, lon2, lat2): """ Calculate the great circle distance between two points on the earth (specified in decimal degrees. But in a kdTree the points are organised in a tree which makes it invalid to use. UPDATE Clarification in response to OP's comment:. association between the categorical. The free parameters of kernel density estimation are the kernel, which specifies the shape of the distribution placed at each point, and the kernel bandwidth, which controls the size of the kernel at each point. One such task might be calculating the great circle distance (GCD) of two points on earth, which can be done with the haversine formula. For example, Euclidean distance between the vectors could be computed as follows: dm. 080036. The resulting formula has just one trigonometric call, making it much faster than the trigonometry-heavy Haversine formula. This is the method recommended for calculating short distances by Bob Chamberlain ( rgc@jpl. The Haversine formula is as follows: the distance using two points as input can be writen as below: def haversine (point1, point2): """ Calculate the great circle distance between two points on the earth (specified in decimal degrees) """ lon1, lat1 = point1. This is an interesting exercise in spherical coordinates, and relates to the so-called haversine. Vectorised Haversine formula with a pandas dataframe. import numpy as np import pandas as pd from sklearn. The Haversine formula is more robust for the calculating the distance as with the spherical cosine formula. Create polygons for each point (function below) with the formula then filter points inside from the master list of points and repeat until there are no more points. To calculate the distance between two GPS points, we can use the Haversine formula. Python function to calculate distance using haversine formula in pandas - Stack Overflow Python function to calculate distance using haversine formula in. - Δlat is the difference between the latitudes. It gives the shortest distance between the two yellow points. See. I would like to know how to get the distance and bearing between 2 GPS points. Set of algorithms and structures related to geodesy. Meaning, the further the geodesic distance between the two coordinates on the ellipsoid - the larger the delta between. newaxis])) dists = haversine. I try to calculate haversine distance between 4 columns. 48095104, 14. Calculate the Haversine distance (in KMS) between the city cluster and the city coordinates using the custom build python UDF function. I know I can compute the haversine distance between two points. def haversine(lon1, lat1, lon2, lat2): """ Calculate the great circle distance between two points on the earth """ # convert decimal degrees to radians lon1, lat1, lon2, lat2 = map(F. Given two points on a sphere and θ being the flat angle between radii connecting those points with the center of the sphere, the haversine formula expresses the haversine function with the lattitude (φ) and longitude. File "", line 8, in haversine TypeError: must be real number, not Column. The great circle method is chosen over other methods. It also provides inverse haversine formula, inverse inverse haversine formula, and inverse haversine vector formula for finding points from vectors or directions. haversine . Considering the dataframes you provided, here is one way to do it with GeoPy distance function, Python built-in zip function and defaultdict class from the standard library's collections module:. The radius r value for this spherical Earth formula is approximately ~6371 km. I have 2 dataframes. For. We will import the libraries and set two sample location coordinates in Melbourne, Australia: import numpy as np import pandas as pd from math import radians, cos, sin, asin, acos, sqrt, pi from geopy import distance from geopy. values dm = scipy. The first distance of each point is assumed to be the latitude, while. pip install haversine. Ch. Raw. sklearn. 2) The documentation says,"Note that the haversine distance metric requires data in the form of [latitude, longitude] and both inputs and outputs are in units of radians. When used for points on the Earth, the calculated distance is approximate as the formula assumes the Earth to be a perfect sphere. Using the implementation below I performed 100,000 iterations in less than 1 second on an older laptop. 882000 3 45. If the distance between any two locations exceeds this threshold, they should be added to a list. py","contentType":"file"},{"name":"haversine. To visualize the calculation, we can draw a Polyline between the two markers. It does not know to unpack the row into the fields that you want. I need help with rearranging the Haversine formula, which is commonly used for calculating the Great Circle (GC) distance between two known points. hstack ( (lat [:, np. The implementation of haversine used here does not work out of the box with array-like objects for longitude and latitude. Generated by CODECOGS. As Anony-Mousse says: As Anony-Mousse says: Note that Haversine distance is not appropriate for k-means or average-linkage clustering, unless you find a smart way of computing the mean that minimizes variance. Comentado el 3 de Septiembre, 2019 por arilwan. The Haversine formula is a mathematical formula that gives the distance between two points on the surface of a sphere. Usted me ha dado una indicación: haversine formula Es la primera vez que escucho esto, gracias. index,. import numpy as np def Haversine(lat1,lon1,lat2,lon2, **kwarg): """ This uses the ‘haversine’ formula to calculate the great-circle distance between two points – that is, the shortest distance over the earth’s surface – giving an ‘as-the-crow-flies’ distance between the points (ignoring any hills they fly over, of course!). def haversine (lon1, lat1, lon2, lat2): """ Calculate the great circle distance between two points on the earth (specified in decimal degrees). d(u, v) = max i | ui − vi |. With cyc_pos defined in that way, obtaining the distances of each point in the latitude-longitude grid to each cyclone center using the haversine function is fairly straightforward, and from there obtaining the desired mask is only one more line. Q : Is the approximation of the radius of 3958 miles good for calculating the distances between the question points?1 Answer. Python function to calculate distance using haversine formula in pandas. It is. Rust, and Python (though not so much in Python as it already has a pretty good set of libraries). The latter, half a versine, is of particular importance in the haversine formula of navigation. This method. The haversine formula determines the great-circle distance between two points on a sphere given their longitudes and latitudes. Currently explicitly supports both cardinal (north, east, south, west) and intercardinal (northeast, southeast, southwest, northwest) directions. fit (np. It is based on the WGS 84 reference ellipsoid and is accurate to within 1 mm (!) or better. The formula itself is simple, and it works for any pair of points that are defined according to their radial coordinates for a given radius: The haversine formula helper function calculates these Greatest Circle Distances (GCD) [3]. 652 km between these. This allows dynamic analysis of the customers, flows, weight, revenue, and any other value within the selected distance. So if I understand correctly, this might help; using the apply function on a frame gives you access to the values of a row, meaning you dont need to convert the columns to lists. 2. Here is a Python code that implements the Haversine formula: python import math def inverse_haversine(lat1, lon1, lat2, lon2): """ Calculates the inverse haversine distance between two points on Earth. PI / 180; } var lon1 = coords1 [0]; var lat1 = coords1 [1]; var lon2 = coords2 [0]; var lat2 = coords2 [1]; var R = 6371. Then to calculate distance between one point to others, I have searched around and found this algorithm that can be converted to DAX: Km = var Lat1 = MIN(‘From’[Latitude])This was a Python project which: Used the Pandas library to take data Filtered it to only consider problem customers Use the haversine formula to direct the problem customers to their nearest network exchange Display the link using a heat map Display the statistics of certain problem exchanges onto a website. Calculate in Python Calculate the distance between two given latitude and longitude points using the Haversine formula. The Law of Supply & Demand seems alive and well in King County, WA. Question: Problem 1: Haversine Distance Finding the distance between two points p1 = 21,41),p2 = 12, y2), d(P1, P2) in a 2D plane is straightforward: d(p1, p2) = [(21 - 2)2 + (y1 - y2) 211/2 When calculating the distance on the Earth, however, we have to take into account Earth's shape. The Haversine formula allows you to calculate the distance between two locations using latitudinal and longitudinal coordinates. Haversine Vectorize Function. 4. deg2rad (locations2) return haversine_distances (locations1, locations2) * 6371000. From haversine's function definition, it looked pretty parallelizable. 000015″ of bearing; the Haversine formulas are accurate to approximately 0. I have this Python function that computes the great-circle distance between two points, but I want to modify it so that a third parameter, altitude, can be incorporated into the Haversine formula. Bearing between two points. Elementwise haversine distances. We can create our own implementation of the Haversine or the Vincenty formula (as shown here for Haversine: Haversine Formula in Python (Bearing and Distance between two GPS points)) or we can use. bounds [0], point1. 3639)Finding the Shortest Route. python spatial-analysis haversine latitude longitude spatial-data haversine-formula distance-calculation vincenty vincenty-inverse Updated Mar 9, 2023; C;. However, even though Vincenty's formulae are quoted as being accurate to within 0. Pandas: compute oriented distance to the next true. , whose minimum distance from source is calculated and finalized. Here’s an example Python implementation of the Haversine formula for calculating the distance between two points using their latitudes and longitudes. While more accurate methods exist for calculating the distance between two points on earths surface, the Haversine formula and Python implementation couldn’t be any simpler. Jean Brouwers has made a Python version. r is the radius of the earth. 129212 51. Geod (ellps='WGS84') fwd_azimuth,back_azimuth,distance =. Let me know. 30+ algorithms, pure python implementation, common interface, optional external libs usage. bounds [0], point2. 0. C. Implement a function forYes, you can certainly do this with scikit-learn/python and pandas. Here's the code for this part. Learn how to use the haversine formula to calculate the distance and bearing between two GPS points in Python, with examples and code snippets. La formula asume que la Tierra es completamente redonda, con lo que cabe. Haversine Formula for Calculating GPS Distances Geospatial analysis is such an interesting field of technology that deals with latitude, longitude, locations, directions, and visualization of course. astype (float). 329 5. As with anything "better" is a matter of your particular application. We can now define the formula of haversine for calculating the distance between two points in the spherical coordinate system. Then you can pass this function into scipy. Luckily, you don’t need to do the calculation by hand. sphere. The radius r value for this spherical Earth formula is approximately ~6371 km. py that returns the distance using haversine formula and the bearing angle between two geographic. Let’s have a look at the haversine formula: a = sin²(Δφ/2) + cos φ1 ⋅ cos φ2 ⋅ sin²(Δλ/2) c = 2 ⋅ atan2( √a, √(1−a) ) Distance = R ⋅ cHow to Prepend a List in Python? (4 Methods) Django VS Flask: A Detailed Look at Python Web Frameworks Top Mistakes that Python Programmers Make; Haversine Formula for Calculating GPS. Below are the detailed steps used in Dijkstra’s algorithm to find the shortest path from a single source vertex to all other vertices in the given graph. You're not going to be able to match it even by adjusting the sphere radius in a Haversine formula. UPDATE Clarification in response to OP's comment:. Someone told me that I could also find the bearing using the same data. double _haversin(double radians) => pow(sin(radians / 2), 2); The distance the function takes four arguments: lat1, lon1, lat2, and lon2, which are the latitude and longitude of the two points. Getting distance from longitude and latitude using Haversine's distance formula. haversine=True uses the haversine formula, which is consideered superior for short distances (which is my often use case). Save the features using fnEngineerFeatures To add the computed value to a table that can be used for training the model, you'll use the custom T-SQL function, fnEngineerFeatures . Source:. The python package haversine was scanned for known vulnerabilities and missing license. The Haversine formula enables us to calculate the distance between two points. The haversine formula determines the great-circle distance between two points on a sphere given their longitudes and latitudes. I was comparing the accuracy between haversine vs Vincenty. Django VS Flask: A Detailed Look at Python Web Frameworks Top Mistakes that Python Programmers Make; Haversine Formula for Calculating GPS Distances; 3 Effective Methods for Applying Gaussian Filters to Images; Python Equivalent of Histfit and Fitdist; Python Equivalent to Matlab’s Bwdist: A Comprehensive Guide; What Is Carry. Add the following lines after the markers in the. The Haversine formula converts locations to radians and uses those values to compute the direct distance in miles between those two locations. Return the store number. Then use a vectorized implementation of haversine like the one found in this answer - Fast Haversine Approximation (Python/Pandas). Before we get into the details of the formula, let's talk about why we should consider augmenting the location data at all. But simple Euclidean distance doesn’t cut it since we have to deal with a sphere,. This is all of my python code and it is very far off from returning the correct distance. Python implementation of haversine formula to determine the great-circle distance between two points on a given sphere knowning their longitudes and latitudes. 9990 4. For each observation in df1, I would like to use the haversine function to calculate the distance between each point in df2. One can derive Haversine formula to calculate distance between two as: a = sin² (ΔlatDifference/2) + cos (lat1). If the distance reaches 50 meter i simply save that gps coordinates. This uses the ‘haversine’ formula to calculate the great-circle distance between two points – that is, the shortest distance over the earth’s surface. Learn how to use the Haversine distance formula to calculate the angular distance between samples in X and Y, a good approximation of the Earth surface. haversine function found here as: print haversine (30. #import modules import numpy as np import pandas as pd import geopandas as gpd from geopandas import GeoDataFrame, GeoSeries from shapely import geometry from shapely. To reduce computational complexity for an embedded system, rather than use the more accurate Vincenty that uses the WSG84 ellipsoid, I have decided to use haversine to calculate the angular distance over a great circle arc then multiply that with the Earth radius. 2. And your function is defined as: def haversine (first,. 5 seconds. apply (lambda x: haversine (x ['Start Station Lat'],x ['Start Station Long'],x. 1. Implement1 Answer. Learn more… Top users; Synonyms. It also provides inverse. 3. Speed = distance/time. timeout – Time, in seconds, to wait for the geocoding service to respond before raising a geopy. def haversine (lon1, lat1, lon2, lat2): lon1, lat1, lon2, lat2. scale () function. Fast Haversine Approximation (Python/Pandas) 16. 追記 (2019-01-08) @knoguchi さんのコメントに記載がありますように、Haversine formula法はGPSウォッチの実測値と少し乖離があるそうです。 より精度の高い計算については 同コメントを参照ください。 情報とv0.