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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1answer
145 views

How to measure distance between points based on elevation?

I need to be able to measure distances between points, however the distance need to be calculated in relations to elevation. The points are homes of storytellers from the 19th century and the places ...
0
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0answers
19 views

Distance Hexagons in CartoDB

I found this blog very interesting and the maps very cool. The code used to produce the hexagon distance maps is not working for me however. This is the code used (from github): select * from ( ...
3
votes
1answer
51 views

How can I find small distance between polylines?

I`m trying to find lines which have small distance between them and I am using ArcGIS 10 for this. I had tried to make points at the both ends of the lines and to detect the distance between points ...
4
votes
1answer
61 views

How to create a map colored by distance to nearest point in R

I'm new to GIS and R-- hope this question makes sense. I have a dataframe(geo07) containing two variables that record the long/lat values for about 6000 points (mat_long & mat_lat). These ...
3
votes
3answers
339 views

QGIS spatial join, calculating distance from polygon to point layer

I am trying to perform a kind of 'spatial join' in Arcgis, joining to a polygon layer atributes of the closest feature of a point layer, as well as distance. But 'spatial query' doesn't offer an ...
0
votes
1answer
79 views

calculate distance between points crossing the antimeridian

How can I calculate the distance between two points (lon/lat) if any of the points exceeds the antimeridian (+-180 longitude)? Im using the distVincentyEllipsoid {geosphere} to calculate the shortest ...
6
votes
2answers
2k views

QGIS calculate distance of point along a line

I have a polyline (movement path) and points recorded along the line. I would like to calculate for each point the distance along the line in Quantum GIS. I hope for a result which will add a new ...
3
votes
4answers
1k views

Calculate min distance between points in PostGIS

I have point layer in PostGIS database. Help please with query which add for each points in layer distance in attribute table between this point and another nearest point. Thanks! Update Calculate ...
2
votes
1answer
68 views

How to calculate which zip code is closer to which in USA using C#?

I'm not living in USA, and I'm doing a small project for a company based in USA. The point is that, there are businesses and each of them have their address and zip code. Then, I have a form where ...
2
votes
1answer
593 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 ...
3
votes
1answer
1k views

WGS point to WGS line segment (great circle) distance

How would I go about resolving this in C#? I have a line segment (great circle distance) defined by two Lon-Lat pairs (call them points A and B). A third point somewhere on the Earth sphere. The ...
1
vote
1answer
122 views

How to calculate the shortest geographical distance between a line and a point? [duplicate]

I'm trying to calculate the shortest distance between a line (described as a pair of [lat, long]s) and a point (lat, long) accurately. I've read many Wikipedia pages, but I'm new to the topic. I've ...
1
vote
1answer
78 views

QGIS distance from points to nearest line

How can I get the distances from each point at a shapefile to the nearest line from another? I've tried to follow the directions from Measuring the distance between lines and points in QGIS and ...
2
votes
2answers
58 views

Distance from centre point to other points using QGIS?

I have a question of something I actually thought was pretty simple...I have a few points around a centre point. Now I want to know the distance from each point to the centre point. Is it possible to ...
6
votes
2answers
787 views

Get shortest distance between two geometries in ArcPy

I'm using ArcPy and using a cursor to step through one polygon feature class. For each of these 'source' polygons, I am creating a SearchCursor to find all polygons in a second feature class that ...
3
votes
1answer
78 views

PostGIS: Get closest point between geometry and Multipoint

I think my question is not that difficult for GIS professionals, but i didn't found an answer to my problem (even not in other questions). Problem: I have given two tables (table1,table2) with Points ...
1
vote
0answers
55 views

Finding areas with high POINT density from PostGIS table using Python

I have a PostGIS table with thousands of POINT objects and I want to find areas that have a high density of points. I have the DBSCAN clustering algorithm implemented in Python which does exactly ...
0
votes
1answer
81 views

The ratio Pixel distance to geographical distance?

I have had this problem for several days and I have no idea to solve it. The problem is that I am trying to find out the length and width of ships from a Bing map. I got the location point (lon, ...
0
votes
0answers
24 views

Calculation size limit to creating distance matrix using QGIS?

I have a shapefile of postal code for a city (Montréal). I would like to calculate the distance between all postal code. I tried to run the distance matrix after converting all postal code to a ...
2
votes
3answers
96 views

Find point close to points from postgis table

I have a postgis point table with a large list of cities. I need to find duplicates in it, but only if they are 10km close each other, which means that is the same city. For example, I have 5 points ...
2
votes
1answer
82 views

Performing Point Distance analysis using Basic level license of ArcGIS for Desktop?

I am using ArcView Version 10.1 and I need to perform a point distance analysis like: What is the distance from A to B-Z, B to A-Z, C to A-Z, etc? What are the steps that I take to do this?
2
votes
0answers
71 views

Calculating Distances between coordinates

I have perused through the other questions that are very similar to mine but am still having some trouble. I have 75 coordinates in WGS84 that I brought in from an Excel table. They are now on my ...
6
votes
1answer
106 views

Statistics: Estimating U.S. population-weighted average temperature from 100+ daily airport station measurements

I have recently signed up for a developer's key for the Census API (http://www.census.gov/developers/) and will be using a Python wrapper class to access the Census database. My goal is to find the ...
3
votes
1answer
62 views

<#> doesn't give a useful distance [duplicate]

I'm new to postgresql/postgis and trying to measure a distance. So st_distance() may be the most accurate, it's the slowest too (as I've read). I read that one can use geometric (instead of ...
3
votes
2answers
95 views

Measuring Continuous Distance of GPS track in ArcGIS Desktop

I am looking for a way to quickly measure the distance covered of GPS tracks of foraging Seabirds. A tool that could give accumulative distance of point to point from the long and lat coordinates ...
3
votes
1answer
79 views

Calculating distances from points to the centre of cells

I am using QGIS 1.8.0 (using older version because I need the Qmarxan plugin which is not available for 2.4.0). I have a study area that has a vector laying of "planning units", or cells over the top ...
2
votes
0answers
28 views

How to calculate distance from point to polygon with a time frame?

Using the Near tool, I knew that I can just calculate the distance of each house to the nearest fire. However, I only want to keep fires that happened in the past 7 years for each house. For example, ...
4
votes
1answer
161 views

What is an efficient Algorithm to draw a straight line from points?

I have some cross section survey data, which is like this: X Y Z pt_dt 2970969.635 359725.0088 83.4242 1-x 2970968.278 359722.2182 83.2591 1-x 2970941.771 359670.127 83.0655 1-x 2970961.369 ...
2
votes
0answers
142 views

Create circles around a point on a map measuring the radius in hours

Disclaimer: I am not experienced in GIS and hope this question fits in this category. I was wondering whether it is somehow possible to create a circle* around a city, using Google Maps or the like, ...
2
votes
3answers
119 views

How to measure correct distances in a project with OpenLayers background?

I have 3 lat/long points as follows: A = {35.257246,139.721256} B = {35.256541,139.721491} C = {35.256326,139.7203271} 1) Measurement result by Movable Type Scripts: By using the distance ...
20
votes
6answers
12k views

Trilateration using 3 latitude and longitude points, and 3 distances

I want to find out an unknown target location (latitude and longitude co-ordinates). There are 3 known points (latitude and longitude co-ordinate pairs) and for each point a distance in kilometers to ...
9
votes
4answers
9k views

How to generate random locations nearby my location?

I am trying to create random locations nearby my location. What i want is to create random latitude/longitude pairs inside a 200 meters circle surrounding my location. This is the formula i came up ...
8
votes
3answers
769 views

What kinds of line segments/edges require high accuracy in a true surface-of-the-ellipsoid representation?

I've been musing (and doing prototype coding) for a 'projection free' geographic codebase with your basic point, line & polygon primitives. Rather than dealing with all the sacrifices that come ...
5
votes
2answers
263 views

Is there a way to calculate closest distances to a point without using Near Analysis?

I frequently get asked to calculate distances from a specific point (A drilling well in the middle of the sea for example) to a number of Environmental layers (Protected Areas, Pipelines, Other wells ...
2
votes
1answer
45 views

Calculate distance for point to point based on value in field of first point

I am trying to figure out the best way to calculate the distance for each student from the school they attend. We have 2 shapefiles - the student locations with a field identifying the school they ...
4
votes
3answers
3k views

How to properly utilize DWITHIN Spatial Filter in OpenLayers

Given the following code: var points = []; points.push(new OpenLayers.Geometry.Point(-110, 38)); points.push(new OpenLayers.Geometry.Point(-108, 40)); var lineString = ...
1
vote
1answer
173 views

Calculate distances between polygon centres in QGIS

Is there a practical way to calculate distances between polygon centroids in QGIS? I have a UK city region map divided into administrative units (1 ward = 1 polygon). I want to represent their ...
1
vote
2answers
76 views

How to show average walking distance to closest point in census tract in ArcMap?

Given a map layer of point locations, and a second map layer of census tract polygons for the same area, how would you create a map layer that shows the average walking distance to the closest point ...
-1
votes
1answer
33 views

Buffering algorithm [closed]

Does anyone know the algorithm of buffering? I had difficulty in drawing buffers. So I tried many values to acquire 1km buffer. I found value 0.008966 produces 1km buffer. Then I calculated inverse ...
7
votes
1answer
238 views

How do I calculate Manhattan distance with PostGIS?

I am using the ST_Distance function to calculate the distance between two geometries (a train station and a building) Since I know that all buildings and all train stations are in Chicago, which has ...
1
vote
0answers
27 views

Scale on map requires correction coefficient. But why?

I am computing the distance of a map I am getting from ArcGIS' REST services by using a calculator as provided by this answer. In a nutshell, it uses a GeodeticCalculator for distance computation ...
2
votes
0answers
110 views

How to calculate the average distance among set of points as measure of closeness

I have three series (or tables) of points in PostGIS which I want to compare. I would like to know how "close" each series is when compared to the other two. In other words I would need some measure ...
1
vote
0answers
39 views

How to set a defined distance between nodes to digitize in qgis?

Using QGIS (by now I have the 2.4 version) I would like to set some parameter (I don't know if such exists) that would impose a definite or maximal distance between nodes when digitizing a polyline or ...
1
vote
1answer
121 views

Distance Between Two Points vs Length of Linestring

So I have two points that I want to calculate the distance between. If I use: SELECT ST_Distance_Spheroid(point_a, point_b, 'SPHEROID["GRS 1980",6378137,298.257222101]') / 1000 FROM ( ...
1
vote
1answer
98 views

GeographyFromText and ST_SetSRID+ST_MakePoint different results?

Why am I getting different results? SELECT ST_DISTANCE( ST_GeographyFromText('SRID=4326;POINT(13.401111 52.383343)'), --berlin ST_GeographyFromText('SRID=4326;POINT(9.997559 53.533778)') ...
3
votes
2answers
192 views

How to calculate the distance of sites to riverways

How do you calculate the distance of about 10 sites scattered across a region to bodies of water (rivers and lakes) using ArcGIS 10.1? I have the lat/lon coordinates of the 10 sites as a point ...
0
votes
0answers
144 views

How to calculate distance between point feature to multiple polyline features in ArcGIS

I have a GPS track which is basically a point layer. I have different route networks such as - train, tram and bus routes. I want to calculate the distance between each point to nearest features ...
2
votes
0answers
90 views

GeoDjango order_by('distance') not working as expected?

Using GeoDjango, I am trying to sort a list of users based on the distance from a point. It does generate a list, but its not ordered by distance, though I specify that in my query. This is the query ...
2
votes
2answers
123 views

Calculating distances between consecutive points along rivers (polygon) using ArcGIS Desktop?

I have radio-tracking locations of semi-aquatic mammals. Now, I would like to calculate the distance between the consecutive locations using the river as the animals would swim (opposite to as the ...
1
vote
0answers
37 views

Calculate distance in point collection algorithm

I've got collection of points which are sorted by x,y and distance between n and n+1 (array of objects [{x:0,y:0},{x:1,y:1}....] I would like to calculate distance between all points (point 1 distance ...