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

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2
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0answers
60 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 ...
1
vote
2answers
410 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 ...
8
votes
3answers
443 views

New to ArcGIS and want to compute distance between two points “as the fish swims”

We have a layer named Hydrography which is the water area for a given assignment. I have a station point and a target point. I need to compute the distance between those two points but inside of the ...
5
votes
1answer
1k views

Shortest distance from point to line (big dataset)

What is the best method to calculate the distance from the nearest road for a series of address points in QGIS, having a very big dataset? (QGIS 2.0.1, Win XP) I read the answers to previous similar ...
0
votes
1answer
82 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
votes
2answers
316 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. ...
1
vote
1answer
687 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 ...
0
votes
1answer
774 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 ...
5
votes
3answers
148 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
143 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). ...
1
vote
1answer
258 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 ...
2
votes
2answers
304 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 ...
0
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0answers
100 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 ...
1
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0answers
122 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 ...
1
vote
0answers
169 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 ...
3
votes
2answers
110 views

Determining closest representation of polygon as collection of points+radii

Have a bit of a tough question, which I realize there may not be an easy solution to. Figured what better place to ask. I'm attempting to transform a polygon into a series of arbitrary points with ...
1
vote
3answers
1k 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
votes
0answers
285 views

How to calculate the distance to multiple locations from each cell of my raster?

I'm working with Arcgis 10.1 and Python 2.7.2 How can I calculate the distance to multiple locations from each cell of my raster? I tried euclidean distance but it only provides the distance to ...
0
votes
3answers
197 views

Computing distance of a georeferenced .jpg to each polygon (town) in a shapefile

I have a .jpg that is a highway that spans multiple towns, and a shapefile with boundaries of these towns. I have georeferenced the .jpg so that it is aligned with the shapefile of the towns. My ...
1
vote
1answer
111 views

Converting NEAR results to Meters/Kilometers?

I am having trouble figuring out how to convert the units from the results of my NEAR calculations. I want to convert them to meters or kilometers, but cannot figure out how to do so... ...
2
votes
2answers
301 views

minimum distance from the shore (how to retrieve the “shore vertices”)

I am student of Statistics, this is my first time using GIS., I am sorry for the stupidity of the question but I browsed online and could not find a satisfactory answer. I have some spatial data in ...
2
votes
1answer
68 views

How to compute the distance from the beginning of a line for every points using postgis

I have a line, for which I need to know, for every point that compose it, what is the distance from the beginning. The data is stored in PostGis 2.0 For example, for the line with the point a, b, c, ...
2
votes
1answer
98 views

Calculating point proximity in ArcMap 10.1

I have a geocoded point file which (theoretically) contains one point for every zip code in the U.S. I want to create a smaller list of zip codes from this file. The list should include only those zip ...
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0answers
121 views

Can QGIS Measure Line tool compute correct geodetic distance?

As I understood, this tool normally shows distance in the project CRS units, not the geodetic meters (despite it actually says the distance is in meters). However, now I read (Section III, 4 - ...
0
votes
1answer
538 views

Specifying a rectangle as two latitude/longitude pairs, one for center and one for size

I am trying to make sense of the Google S2 library for spherical math (it works like this). I need to get a rectangle for searching for nearby entities in a database, based on a point and a distance ...
2
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0answers
197 views

Specifying a bounding rectangle using Google's S2 package for spherical geometry [duplicate]

This is my first post on GIS, I hope it is not too trivial a question. I work on a project on Google AppEngine, which is backed by a NoSQL datastore. This makes a proximity filter different from ...
2
votes
1answer
77 views

Where would a perfectly vertical vertical tunnel through the earth come out?

I am a programmer. I have a point P1 (lat,lon) given by GPS (WGS84) and I want to know the location of a point P2 if I make a straight line from P1 to the other side of the earth. I have read some ...
4
votes
1answer
295 views

meeting point minimizing travel distance for participants?

The problem is to find the point minimizing the travel distance for around 100 persons in different regions who want to meet in the same place. Travel is by car not by plane. Assuming that I get ...
7
votes
2answers
896 views

projection change to create buffer in QGIS

I am about to become desperate... I like to create buffer around several points - if possible - with a declaration of the size in km of these buffers. Just to show you what I am working with: My ...
4
votes
2answers
423 views

How do I find the average distance within a polygon to a point?

For my purposes, I can assume a homogeneous distribution of points within the polygon. What I want to find is the average distance from points within a polygon to a specified point. I don't know where ...
0
votes
1answer
104 views

How to visualise “distance from amenities”?

I'm interested in calculating for every point the distance to the nearest amenity of each of a certain number of types (train station, supermarket and so on). I think the calculation will be ...
1
vote
1answer
86 views

PostGIS integer loop

PostGIS is very new to me, and I'm having difficulty performing an operation that probably isn't too difficult. I have vector layers each filled with the outline of a landmass through time. I want to ...
3
votes
0answers
158 views

Constructing a Voronoi diagram using a complicated travel time metric

I have in my possession four sets of shapefiles: 1. Locations (points), around 1000 2. Roads (lines), each road has a speed attribute 3. Terrain (polygons), each zone also has a speed attribute 4. ...
0
votes
1answer
181 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 ...
1
vote
2answers
250 views

find latlngs that are some x distance away from a point to south to north to east to west

I have a latlng i want to find four points with equal distance from this latlangs in all directions east, west, south an north is there any formula . I am trying to build polygons around higways so ...
4
votes
1answer
112 views

How to calculate average distance from points to points?

I have a point layer of 400,000 voter residencies and a point layer of 500 polling places. I am trying to find the average distance it takes voters to get to their polling location. Distance by road ...
3
votes
3answers
334 views

Why is sum of st_length() of segments 20% too big?

I'm running a query to return the total length of some bike paths, from OpenStreetMap. Compared to the known actual length of these paths, they're all a bit too big - something like 10-30%. I know it ...
1
vote
1answer
299 views

QGis creating shape file of several points out of two Excel sheets

I am about to create a Qgis file on which it should be visible which companies are working together. As source I have got two Excel Tables. Table = Distribution Centers Table = Point of sales I ...
0
votes
0answers
373 views

Bearing Distance to Line tool from dBASE table only draws one line in ArcGIS 10

I am using the Bearing Distance To Line tool to draw geodesic lines to points defined by a bearing and distance. This is an aside, but I will then use the Feature Vertices To Points tool to convert ...
1
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0answers
49 views

windows function with points in a mixed (multipoint/point) table

I have a table comprising multipoints (tracks) and points (stops between tracks). there can be several consecutive multipoints. now, i want to merge any points lying very closely to each other ...
1
vote
1answer
1k views

Distance between DB field and Point using PostGIS

I'm using Postgresql 9.0 with PostGIS 2.0 extension. I've got the table and geographic field location: =# SELECT * FROM geography_columns; f_table_catalog | f_table_schema | f_table_name | ...
4
votes
2answers
586 views

ST_Distance is not delivering right results

I want to calculate the distance between lat/lon points. I tried the following queries: Select ST_DISTANCE(ST_GeomFromText('POINT(-73.97923 40.75571)', 4326), ST_GeomFromText('POINT(-73.974509 ...
5
votes
2answers
331 views

How to create a point along a line given a distance from another point

I'm trying to figure out a point(D) on B-C that is a specific distance from A. I really don't have any idea on how to proceed with the ellipsoidal math so I figured I'd ask here. How would I figure ...
0
votes
0answers
23 views

Asp code for distance in SQL sever

I've looked around but I can't find the answer anywhere and im getting kinda frustrated now. I'm using sql server and what im trying to do is to find apartments within a 0.5km radious of a said ...
8
votes
1answer
271 views

How to automatically reduce polygon size?

I am working with two polygon layers (counties & states) which I will 'intersect' to find which counties are within which states. Due to data inaccuracies I have to change all county polygons and ...
0
votes
1answer
74 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 ...
0
votes
2answers
455 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 ...
4
votes
1answer
193 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 ...
3
votes
1answer
46 views

Does IDistanceOP.EucDistanceFull require a projected coordinate system?

I have designed an implementation of ArcObjects' IDistanceOP.EucDistanceFull. It takes its input as a feature class and converts it to a GeoDataset with which EucDistanceFull can work with. It works ...
2
votes
1answer
515 views

Create raster distance around a single point feature class

Okay, so I'm relatively new to ArcMap and I'm trying to use the Fuzzy membership for suitability test. I have a single point feature class that I want to use for this analysis. I know that in order to ...