distance

Distance calculation from my location to destination location in android

check the documentation on the google android dev page to see how to listen for position changes. http://developer.android.com/guide/topics/location/obtaining-user-location.html you can use this function to determine the distance between the current (start) point and the target point. /** * using WSG84 * using the Metric system */ public static float getDistance(double startLati, double startLongi, double goalLati, … Read more

Edit Distance in Python

The thing you are looking at is called an edit distance and here is a nice explanation on wiki. There are a lot of ways how to define a distance between the two words and the one that you want is called Levenshtein distance and here is a DP (dynamic programming) implementation in python. def … Read more

Calculate distance in meters when you know longitude and latitude in java [duplicate]

Based on another question on stackoverflow, I got this code.. This calculates the result in meters, not in miles 🙂 public static float distFrom(float lat1, float lng1, float lat2, float lng2) { double earthRadius = 6371000; //meters double dLat = Math.toRadians(lat2-lat1); double dLng = Math.toRadians(lng2-lng1); double a = Math.sin(dLat/2) * Math.sin(dLat/2) + Math.cos(Math.toRadians(lat1)) * Math.cos(Math.toRadians(lat2)) … Read more

R – Finding closest neighboring point and number of neighbors within a given radius, coordinates lat-long

Best option is to use libraries sp and rgeos, which enable you to construct spatial classes and perform geoprocessing. library(sp) library(rgeos) Read the data and transform them to spatial objects: mydata <- read.delim(‘d:/temp/testfile.txt’, header=T) sp.mydata <- mydata coordinates(sp.mydata) <- ~long+lat class(sp.mydata) [1] “SpatialPointsDataFrame” attr(,”package”) [1] “sp” Now calculate pairwise distances between points d <- gDistance(sp.mydata, … Read more

Efficiently compute pairwise squared Euclidean distance in Matlab

The usually given answer here is based on bsxfun (cf. e.g. [1]). My proposed approach is based on matrix multiplication and turns out to be much faster than any comparable algorithm I could find: helpA = zeros(numA,3*d); helpB = zeros(numB,3*d); for idx = 1:d helpA(:,3*idx-2:3*idx) = [ones(numA,1), -2*A(:,idx), A(:,idx).^2 ]; helpB(:,3*idx-2:3*idx) = [B(:,idx).^2 , B(:,idx), … Read more

Calculating distance between two geographic locations

http://developer.android.com/reference/android/location/Location.html Look into distanceTo Returns the approximate distance in meters between this location and the given location. Distance is defined using the WGS84 ellipsoid. or distanceBetween Computes the approximate distance in meters between two locations, and optionally the initial and final bearings of the shortest path between them. Distance and bearing are defined using the … Read more

Geographic / geospatial distance between 2 lists of lat/lon points (coordinates)

To calculate the geographic distance between two points with latitude/longitude coordinates, you can use several formula’s. The package geosphere has the distCosine, distHaversine, distVincentySphere and distVincentyEllipsoid for calculating the distance. Of these, the distVincentyEllipsoid is considered the most accurate one, but is computationally more intensive than the other ones. With one of these functions, you … Read more