The measure of separation between two entities or locations that may or may not be connected, such as two points.

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2k views

Calculate distance in kilometers between two points

I have a few questions regarding the calculation of the distance between 2 postal codes. Take a look at the following code. ### # load the different packages we need ### require("rgdal") ...
28
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2answers
2k views

How accurate is approximating the Earth as a sphere?

What level of error do I encounter when approximating the earth as a sphere? Specifically, when dealing with the location of points and, for example, the great circle distances between them. Are ...
5
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1answer
143 views

Optimize the locations of 2 additional restrooms on a trail (ArcGIS 10.2)

In the image below, the line is a trail and the point is an existing restroom. I would like to find the rough locations of 2 additional restrooms that minimize the maximum distance along trail from ...
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1answer
188 views

Calculation of Euclidean Distance [closed]

What is the best way to calculate the euclidean distance between the elements of two point vector layers, without rasterising the layers? Thanks
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2answers
446 views

Variation of algorithms to find point from another point with bearing and distance

There are several algorithms to calculate distance between two latitude/longitude points. Haversine Hubeny Lambert-Andoyer Vincenty's formulae for inverse problem But there are not so many ...
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1answer
64 views

mile distance around each feature ArcGIS

I have a school layer information and a route map layer. In ArcMap, how can I show the x mile distance around each school base on route information. I did some research and I found different ...
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1answer
156 views

calculate least cost pathways for a region and create distance rasters to rivers [duplicate]

How do you calculate all the least cost pathways that exists for a region? I would like the output map to display all routes (and was wondering whether this can be done in one set of operations). I ...
3
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1answer
30 views

Equidistant projection for northern Delaware

I'm just getting started on a long-term project involving northern Delaware. Most of my distances will use great circle distances from the lat/lon, but for a few applications I'll wind up using ...
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1answer
199 views

Manipulating distances in python. Problem with ShapeLength

I have a question more than a problem. I'm getting the distance of a line using python with arcpy.da.SearchCursor or FeatureClassToNumPyArray. The result I get is a double. Example: ...
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1answer
140 views

How to find features within a distance? [duplicate]

I insert the values from lat/long into the points. Those users move around and send me new Lat/long and of course , I made an update of the position. I need to find people that are in a distance ...
2
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0answers
73 views

coordinate system for calculating distance at the nation scale

I want to use ArcGIS 10.1 to calculate the straight (euclidean) distances from zip codes to their nearest city centers in about 300 U.S. metropolitan areas. I have two point shpfiles: one includes the ...
2
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1answer
159 views

How to find least-cost paths including tunnels (where slopes are too steep)?

I'm currently working on a road path finding project for a motorway in ArcGIS 10. One criterion is obviously the slope angle. What I would like to do is to create a new cost surface which finds ...
2
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1answer
676 views

PostGIS: Calculate the length of just the portion of linestring that intersect with a polygon

I want to calculate the portion of the linestring that lies within the limits of a polygon. Better with an image What is the length of the portion of linestring within Province A? and within ...
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2answers
967 views

Postgis, get the points that are x meters near another point, in meters

I'm trying to find the points within a certain distance, in meters, from another point. I'm using the function ST_Buffer, but I don't get how to express the distance in meters. I'm trying with ...
3
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2answers
199 views

Calculate distance in QGIS, wrong geographic projection?

I'm trying to do the following: I have 2 shapefiles, one containing all the public schools in NY, another one containing the hotspots in NY (both in points form). Now what I'm trying to do is ...
0
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2answers
522 views

Find longitude for point between two coordinates with pyproj?

I've written a function to get the longitude of a point of known latitude between two known points (might not be working correctly yet), but I feel like there must be a better way of using pyproj to ...
2
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1answer
94 views

Road Miles Calculation without Google Maps

We have two ZIP codes we want to calculate the road mile difference. Google maps states you cannot use their API if you do not show a map. Is there another service that provides this type of ...
4
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2answers
400 views

How to calculate the azimuth of a line of a multilinestring in PostGIS?

I have two spatially enabled tables in PostgreSQL with a geometry in each: First table is with POINT type, second is with MULTILINESTRING. I need to calculate the azimuth of the LINESTRING part of a ...
4
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1answer
219 views

How to find Closest Facility (euclidean distance)?

I have some facilities and incidents, and I want to find the closest facility for each incident. I've done it via Network Analyst (with a network dataset) but I'm wondering if you can do it with just ...
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4answers
575 views

How to calculate the “depth” of a linestring using postgis

I have linestring features, which look like bent linestrings, hemicycles or convex or concave linestrings. In the moment I can select the distance between the startpoint and endpoint of each feature. ...
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2answers
825 views

How do I group near points with GPS positions?

I'm an IT person so I don't know too much about projections and so on, I hope you can help me. I have made an application for Android that collects a GPS position, so I have the latitude and the ...
4
votes
2answers
2k views

Spatial distance analysis in QGIS

I'm quite new to QGIS and trying to figure out how to analyze the following problem. I have three layers: settlements point layer with 253 entries waste treatment facilities point layer with 24 ...
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2answers
602 views

How to determine average distance from points to line?

I have a polyline road dataset and a study area (polygon) covering the the road dataset. I want to determine the average distance for every given point within the study area to the nearest road. i ...
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1answer
79 views

QGIS proximity raster with extent beyond original coverage?

I need a raster coverage of distances from points outside the geographic region of interest, and am having trouble doing this with QGIS. Questions like this one (Calculating distance to points in ...
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3answers
1k views

How can I calculate the distances between my points in sequence automatically?

I have a rookie problem (again). I am trying to measure distances between points and writing the calculated measure between these points in the attribute table. The points represents a vehicle's ...
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1answer
52 views

Can distance be calculated to a destination feature based on an attribute in the source?

All, Is it possible to specify which destination point to calculate distance to based on an attribute in the source? STDistance will give me the distance each student (point) is to their closest ...
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1answer
81 views

Point to point distance over specified distance

I need to calculate the distance between neighbouring points which conform to a staggered line. I have two point datasets, one being the baseline and another the monitor. The points typically reside ...
3
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0answers
191 views

converting a distance to a map distance

I have a point and a polyline. I need to find the perpendicular distance between each segment of the polyline and the point. By each segemnt of the polyline I mean that, each polyline may contain more ...
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3answers
2k views

Generate random location within specified distance of a given point

In a simulation (not using any GIS), I need to generate a random location that is within a specified distance of a given location. I found a very helpful post here on this exact topic: How to ...
3
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1answer
1k views

Measuring distance between points along a river system

I have a forked river with multiple x,y data points along it and I need to measure the distance between these points when travelling along the river. However the forked part is throwing a wrench into ...
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1answer
1k views

SQL to get points within a certain distance

I am new to using spatial data types in sql server. I have managed to create a column of Approx 50,0000 geometry points (from x,y data) and would like to find out which (count number of) points are ...
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1answer
136 views

Distance between two latitudes [duplicate]

I need to know the distance in feet between the coordinates N34-00.000 and N34-00.001 (Degrees, minutes and thousanths of minutes) I computed approx 6 feet but am not confidant in my math skills.
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1answer
473 views

Calculate distance to median point for a group of points in ArcGIS 10.1

I have a shapefile called "household_points" of ~2,000 points, which are divided into about 100 sites. The shapefile has a field in the attribute table called "SNAME" and in the field each point is ...
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0answers
66 views

Get distance after path distance allocation

I use ArcGIS 10.1 in Windows XP. I have a two point feature data sets One containing a single point P1 and another containing multiple points Pm. I computed the minimum-distance path from P1 to each ...
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2answers
572 views

Calculating millions of distances with Road Graph

I'm new to GIS but thanks to the answers I got in another question here on GIS stack exchange I was able to increase my knowledge significantly. This question is related to an earlier question I asked ...
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1answer
365 views

Mimimum distance between points (Postgres/PostGIS)

I have a table (tab_Cities with cities which own more than 50000 inhabitants. The table also contains lat, long and the_geom as columns. I can already see the points via QGIS. Now I want to write a ...
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1answer
91 views

Shortest path to nearest… something

I have a list of addresses and a map including train stations, schools etc., and I would like to calculate the shortest distance from each address to the nearest train station, school etc. I'm aware ...
3
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1answer
269 views

finding a location on a line using a point and a relative distance with arcgis js api

The problem I'm trying to solve is to find a point on a line given another point on the same line and a distance from the same point. I've been looking on the various RouteTask examples but they ...
3
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2answers
405 views

How to calculate distances between addresses and cities and coast line?

I am totally new to GIS, and so I apologize if my question is not clear enough. My basic problem is the following: I have about 160,000 Danish addresses with longitude and latitude for each address. ...
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1answer
991 views

Measuring Distance from Point to Point Along a Path in ArcMap

I am looking at a village and want to find the distance from each house (point) to the pagoda (point). However, I want the distance to be measured along a path (which I digitized as a polyline) and ...
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3answers
175 views

What is the precise distance from equator to pole according to WGS84?

For calculating areas of polygons by means of projecting to a cylindrical equal area projection I came across the following discrepancy: I ended up with a different distance, off by more than 5km, ...
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2answers
161 views

Distance between latlongs varies in different projection systems?

I have shapefiles with correct projections. The SRS is EPSG 32735 (WGS 1984 UTM 35S) Now, I have these two coordinates from this projection system: (31.3751,-23.4388) and (31.3779,-23.4355). ...
8
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3answers
686 views

Identification of consecutive points within a specified buffer

I have a point file, hourly relocations of an animal, and I want to be able to place a buffer around each point and calculate the number of subsequent points which are within the buffer zone. I am ...
6
votes
2answers
463 views

Projections appropriate for global analysis that preserve area and that preserve distance (but not necessarily in the same projection)

I am looking for a projection (or a set of projections) that decently preserve distances so that I can buffer every country in the world and have a similar level of minimal distortion for each. I ...
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2answers
457 views

Finding points along a path

I am unsure of the best approach to this problem. I can think of some ways of doing it which I will list below but I am looking for the best and most efficient way of doing this. Problem Given a ...
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1answer
224 views

How to correctly convert data from OSM with osm2po to use it with A* algorithm?

I want to make my A-Star fast, by using heuristics. At the moment it is very slow and even slower than my Dijkstra. I thougt A-Star is in the worst case as fast as Dijkstra. I convert my OSM bounding ...
4
votes
1answer
363 views

How to measure the distance of multiple points to a line

I have two shapfile in QGIS to which I am trying to find the distances between. I have a shoreline which is a vector line and then I have hundreds of data points in the ocean. What I am trying to find ...
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0answers
136 views

Sort a collection of points based on proximity using pythagorean (2D) distance

I would like to present a user with a list of points, sorted by proximity to the user's location. Is there any problem with using the pythagorean formula to calculate the two dimensional distance ...
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0answers
178 views

How to create a buffer around a point that takes terrain elevation in account?

In QGIS, I am creating a few different buffer around points to simulate walking distances. For example, 10 minutes walk about 800m at 5km/h. Using population density, I then clip a population layer ...
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0answers
195 views

Calculate Distance Matrix for ALL possible combinations in the dataset in QGIS

I have a Vector Layer that is created out of a MySQL database and has the relevant points stored in WGS84 format. The import works well, however, when I try to calculate a distance matrix between all ...