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

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1answer
1k views

Getting points within a range from a postgres database?

ok so this is query i'm making which returns no result: SELECT building.gid FROM building WHERE ST_Dwithin(building.geom, ST_GeomFromText('POINT(long lat)',4326), 400) If I run this ...
3
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1answer
968 views

Finding projection of point to line?

I have a segment defined by 2 LatLon points(A and B) and a third LatLon point (C). I need an alghorithm, formulae, or some code to find the projection point of C on the segment AB (call this point D) ...
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3answers
338 views

How to convert points to lines?

I want to convert these points to lines, however they are not sorted sequentially along a line (by ID or FID), i.e. the converted lines zig-zag across the obvious trail of points. How can I join ...
3
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1answer
2k views

How to draw a polygon with preset length in OpenLayers?

For a project I am working on, I need to be able to put a polygon on a map using OpenLayers, based on a variable point that can be set by a user. The polygon is an isosceles triangle of which two legs ...
3
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1answer
1k views

Transform polygon to equivalent circle, QGis

I have a polygon and I'd like to find the radius of an equivalent circle from a particular point within the polygon. The polygon would have a large (infinite) number of points evenly distributed ...
3
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2answers
1k views

Calculating the distance between points and multiple lines?

I have a point shapefile of about 100 points and a polyline shapefile of about 200 lines and I am interested in finding the distance between every point and each individual polyline. My polyline ...
3
votes
1answer
208 views

Proof of part of haversine formula?

I'm trying to study how to find the distance between two points if their latitudes and longitudes are given. I have a question about the proof of part of the haversine formula given at Math Forum. ...
2
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3answers
172 views

Computing distance from points to coastline

I have a shapefile with the nodes of a grid I have applied, for the purposes of interpolation, and I want to compute the euclidean distance that each grid node (it is a point vector) has to the ...
2
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2answers
343 views

QGIS equivalent for ArcMap join for purpose of distances from points to polygon?

It is relatively easy to calculate distances from points to a polygon in ArcMap by doing a join and selecting the option for creating a field containing the minimum distance information. i.e. it ...
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0answers
70 views

How to calculate shortest path from points in one layer to points in another layer via roads, in QGIS

I'm a new user of QGIS (and have experience using ArcGIS but zero programming skills) and I'm looking for a way to calculate the shortest path from addresses to subway stations via a network of roads. ...
2
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2answers
701 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 ...
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0answers
188 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
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1answer
3k views

How to calculate distance between two locations using stored procedure in MySQL?

I have a database with locations with its lat and long coordinates. The area of locations is quite small with lots of them quite near each other. Im using this stored procedure in my project. http://...
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0answers
200 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 ...
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1answer
276 views

Cost Distance interpretation in ArcGIS 10.2

I am using the Cost Distance tool in ArcMap 10.2 to find the how far it is to walk to the closest area of green space along the road network in a town. I have a input raster of the location of the ...
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1answer
2k views

Using Python to compute the distance between coordinates (lat/long) using haversine formula and print results within .csv

I have a .csv file with 3 columns. The first column is titled Distance and it is empty. The second and third columns are titled Longitude and Latitude which contain coordinates, for example: Distance,...
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1answer
594 views

Calculated distance doesn't match Google Earth

I have a google earth route that measures 190.1km in Google Earth. I then pulled down the .kml file, extracted the points and measured them using Vincenty's formula (ellipsoid earth) and got 190.2. ...
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0answers
802 views

How to approximate point to segment distance on sphere?

I would like to approximate the distance of a line segment from a reference point on the map (coordinates are gives as lat/lon). In the Cartesian coordinate system I would simply find the closest ...
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1answer
75 views

Extracting the closest Point to a Line within a Polygon using ArcGIS for Desktop

I have the following shapefiles: Polyline: Detailing a road network. Polygon: Containing approx. 2000 polygons enclosing sections of that road network. Point: Containing numerous (OS Addressbase) ...
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2answers
347 views

Cost-Distance Tool not producing logical answer

I am working on creating a cost catchment based on Tobler's equation in ArcGIS10.1. I feel confident in my cost surface; it produces a raster where each cell equals the time in hours that it would ...
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1answer
323 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)') --...
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0answers
418 views

Why Haversine formula and Web Mercator give different length between two latlng points?

I am calculating the distance between two points given by latlng. However, Google Maps (i.e., web mercator projection) gives me a longer distance than Haversine formula. Which is the most accurate ...
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1answer
370 views

How to calculate the distance to the nearest coastline from site locations?

I want to calculate the distance to the nearest coastline from my site locations (point shapefile), and possibly the max distance as well. I am using ArcGIS 10.2 and I already have a shapefile of the ...
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vote
1answer
163 views

Find nearest road distance between two points for over 1000 points

I'm extremely new to QGIS and am learning the material on my own. I have two CSV files with latitudes and longitudes, one has school address information and the other has fast food restaurant ...
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1answer
96 views

Visualisation of “dominant” point in each location

I had an idea for a kind of visualisation, and I'd like to know if it's been done before, what it's called etc. Basically it would visualise a single numerical quantity that varies greatly, at ...
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2answers
72 views

Distance to, travel only on one surface

Looking to create a distance to wetland raster. However this travel distance must be through the water only. I have tried setting land to a high cost (e.g. 99) however doing so I have to set each ...
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0answers
15 views

Wrong corners distance by geopy's Vincenty Distance formula

I try to calculate distances between corners in raster map. I use answer from this How to get raster corner coordinates using Python GDAL bindings? and make my code. But for some maps results is ...
0
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2answers
194 views

NNJoin, MMQGIS and Nearest Neighbor QGIS failed to measure shortest distance

I have two layers, one point and one line. I need the distance to the closest line from the point layer. Not NNJoin, MMQGIS nor the distance hub in QGIS provided accurate measures. Any ideas?
0
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1answer
168 views

nearest point distance in Arc Map

How do you calculate the nearest distance from one XY coordinate to another XY. I'm using Arc Map 10 I went into Arc tool box -> proximity -> then I only have 2 buffering options. But under buffer ...
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1answer
953 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 (...