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
votes
0answers
36 views

Finding distance between two points and land cover in %? [closed]

I am trying to use ArCGIS. I was using digimap to work out a 2km buffer from a sample point, I managed to do that and saved the file. I also saw some land cover types on the left hand side of Digimap ...
10
votes
3answers
38k views

Find points within a distance using MySQL

I have a mySQL table with user name, latitude and longitude of the user. I would like to get a list of user who are inside the circle or square of a given latitude and longitude with given distance. ...
0
votes
1answer
24 views

Node-line minimum distance: draw the minimum distance point location

I am working with a layer of nodes and a layer of lines. I would need a tool able to find and draw, for some couples node-line, the location of the closest point laying on the line to this node. ...
8
votes
0answers
122 views

Given two lat/longs, how can I tell if they are within 1 mile of each other?

I'm trying to implement a very efficient check to see whether two points are within a mile of each other, or not. My current approach is to compute the Haversine distance, and then check to see if ...
5
votes
0answers
99 views

Finding density centroids within polygons in PostGIS

I want to find the highest density of OpenStreetMap nodes within a dataset of census geometries. I want to tie the census data to the location of the node which is most central in terms of population. ...
1
vote
1answer
63 views

orthogonal projection of a point onto linestring in PostGIS

I am trying to find the orthogonal projection of a Point (in 4326 SRID) onto a LineString (in 4326). The picture shows the objective. I have tried to use ST_Distance function, but in this case the ...
2
votes
1answer
48 views

Distance to nearest cell with value “x”

I would like to create a raster where each cell equals the distance to the nearest cell >= the value of the source cell plus a constant. In the example below, the input raster has a grid size of 1m x ...
0
votes
2answers
54 views

Generating random points near a location [closed]

In the following solution, why is there a sqrt(u)? Since u is just a random number in [0, 1) doesn't getting the sqrt just give you another smaller random number? To generate points uniformly, ...
0
votes
2answers
39 views

Looking for the “inverse” of the NEAR tool

To calculate wind fetch over water I need to create a point on the shoreline and then calculate the distance to to other shorelines all directions (0 - 360 deg). The shortest distance to another land ...
0
votes
1answer
124 views

ArcGIS WebADF Distance tool

Is there a tool in the WebADF that will let me draw a straight line and calculate the distance between the two points.
0
votes
1answer
134 views

Select points within a buffer in QGIS

In my vector layer I want to select points within a buffer of 12 meters and with an exception (if 'Name' is not "James" than select). Is this possible with "select by expression"?
1
vote
0answers
36 views

Calculate shortest paths for each output area in catchment through road network to a single point (i.e. store)

The title sums it up pretty much. I'm looking to derive trip distributions to a single store using population data and distance within a prescribed distance catchment. I have calculated the catchment ...
2
votes
1answer
30 views

Point-Line shortest distance and corresponding angle using FME

I want to determine the shortest distance and especially the corresponding angle from a point to a polyline. A solution using FME would be strongly preferred.
0
votes
0answers
30 views

Compare euclidean distance with network distance

I have a raster file with euclidean distance. It contains information about how long it takes for a chopper to arrive to certain destinations. I then have a polygon made from a service area with ...
25
votes
6answers
24k 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 ...
21
votes
6answers
14k views

How to cluster spatial data in R?

I am very new to R. I have bunch of data points with latitude and longitude. I want to use R to cluster them based on their distance. I have already taken a look at this page and tried clustTool ...
5
votes
1answer
54 views

Pacific-wide Projection for distance?

I have a data set of ~3500 points located across the Pacific Ocean, and am looking to measure the distance from each point to it's nearest coastline to identify the "host" country. I had originally ...
2
votes
1answer
31 views

Finding distance of a building from road junction

I have a peculiar problem which i cannot think of way to solve. I need to find distance of a building from the nearest road junction. This would include distance to the nearest road and how far is ...
0
votes
0answers
53 views

How to calculate multiple travel times using gmapsdistance?

I am trying to use gmapsdistance on R to calculate multiple transit times from Google Maps. I have a Google API key and can generate transit travel times for one origin and one destination with the ...
2
votes
2answers
200 views

Shapely Distance different from Geopy/Haversine

I am running a specific analysis where we use shapely to create buffers around points (store locations) and then check if other points (user locations) are present within that buffer value. When i ...
2
votes
0answers
59 views

Measure distance between points along a line in QGIS

I have a road network and different points connected to the roads. I would like to measure the distance between several points along the roads. Basically I want to do the same like the road graph ...
1
vote
0answers
22 views

Computing intersection of distance circles around fixed points [duplicate]

(to simplify calculations, I assume a spherical earth. All distances are assumed measured "as the crow flies") Suppose we have the lon/lat coordinates for two points (p_1,p_2) less than Nkm apart. ...
8
votes
5answers
5k views

Geodjango- get the distance between 2 points

What I want to do is quite simple, I have 2 locations defined by gps coords, lat / long like returned by google maps: http://gmaps-samples.googlecode.com/svn/trunk/geocoder/singlegeocode.html I need ...
17
votes
3answers
4k views

What is the approximate error of the Pythagorean Theorem vs. Haversine Formula in measuring distances on a sphere at various scales?

Many people when first trying to calculate distances between two longitude / latitude pairs ask if Pythagorean theorem works as an appropriate distance function. Most often people answer "no, the ...
11
votes
1answer
132 views

How big does a circular geofence need to be for the curvature of the earth to matter? [duplicate]

I'm working on adding geofences to a mobile application. I know the proper way of calculating distance between two points on a sphere is using the great-circle or Haversine formula. I don't know if ...
1
vote
1answer
68 views

Get distances between boundaries from an SpatialPolygon and raster pixels

I am trying to calculate the distance from several pixels of a raster to a boundary of some polygons in R as it is showed in the image. I have two problems: How to correctly define a boundary from ...
0
votes
1answer
199 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 ...
2
votes
1answer
61 views

Hive GIS ST_GeodesicLengthWGS84 not returning expected distance

I am trying to find the distance between two points (in meters and not degrees) using GIS Tools for Hadoop by ESRI. The ST_Length provides distance in degrees and hence I used the ...
1
vote
1answer
52 views

cells w/in search window GRASS GIS

I am trying to find all cells that are a certain distance and within a certain window from a cell of interest. For example: I want all cells in a distance of 10m within a search window of 10 - 40 ...
2
votes
1answer
223 views

Measure distance between vertices of polylines in QGIS for Desktop

I have this dataset of coordinates of electric lines in the form of vector polylines as shown in the image below, and I need to measure the distance between the first and last vertex of each line and ...
3
votes
1answer
62 views

How to measure the Speed between two Waypoints?

I'm totally new to QGIS or any GIS. I need to analyze a lot of Waypoints to get the average speed of the people walking between them. (It's for analyzing an experiment I made) therefore I neet do ...
2
votes
0answers
24 views

OpenLayers measurment path in 31700 projection

I have this code who works great for distance measurment on 900913 projection with 4326 display projection (bing maps + layer WMS): measureDistanceControl = new OpenLayers.Control.Measure( ...
1
vote
0answers
60 views

Calculate distance from a point to the border of polygon (US state)

I have a point, and I want to know if it is nearer than 100 miles from some US State border (California for example). I assume that I would need to use this: US Regions State Boundaries. But if I ...
3
votes
2answers
190 views

Measure distances between specific features in QGIS for Desktop

I'm completely new using PyQGIS and developing plugins. Currently I have a layer with the X and Y coordinates of electric distribution poles, where each pole is a feature. What I need to do is ...
1
vote
0answers
28 views

Incorrect results returning from st_distance_spheroid query

Given a routable network table constructed by completing the guide at http://anitagraser.com/2011/02/07/a-beginners-guide-to-pgrouting/, how can I get an accurate list of all roads that are within a ...
45
votes
6answers
15k views

Why is the 'straight line' path across continent so curved?

This is the result of mapping the straight line path from a point in US to Poland using Distance Measurement Tool. Also, planes from Asia to US would travel almost over North Pole. Why is the path ...
2
votes
2answers
43 views

How many query points fall within distance X to a set of LineString

I have a set of 10 query points and I want to know how many of them are with distance within at most 4 meters of any LineString in a given table. Note that if a point is within 4 meter distance to ...
5
votes
5answers
18k views

For every point, distance to nearest polygon of type X?

In ArcGIS Desktop, can you calculate as an attribute value the distance to the nearest polygon of type X? Assume we have a point layer of wildlife observations and we want to know how far each of ...
2
votes
0answers
22 views

Using “snap pour point” to find a watershed of specific area starting from a point

I am trying to find everything downhill of a certain point in order to create a watershed of a specific area. For example, say I have a point at (x,y), and I'm interested in creating a watershed ...
2
votes
1answer
38 views

Calculating distance between points from table of UIDs [ArcMap]

I have a .dbf file containing pairs of point feature Unique Identifiers (UIDs), and need to calculate the straight-line distance between each of these pairs. The XY coordinates of the individual ...
0
votes
0answers
25 views

EPSG:4978 or others for Distance

Usually when I have been calculating distances I project to the system which has the tightest crop around my points e.g. for the UK #http://epsg.io/27700-5339 (accuracy: 1.0m) uk = '+proj=tmerc ...
1
vote
0answers
26 views

Build network based on shortest distance between points

Is there a way to build a network based on the shortest distances between each point of a point layer. I have occurrence data from species (as points) and want to estimate whether there are one or ...
0
votes
0answers
17 views

How to select within a distance using QGIS [duplicate]

With QGIS 2.12.3, I have two projected EPSG:2927 point shapefiles, A and B. I would like to create a selection of A points that are within 100 meters of any B point. This is easy in Arc, using the ...
3
votes
0answers
63 views

How to calculate best path between 2 points from a DEM in Qgis?

I'm analyzing the roads and paths of a region by calculating how effective the communication is in the region. First I calculated the shortest paths between the points using the actual road map. Now ...
3
votes
2answers
44 views

Calculating areas outside a point

I have a university assignment that requires me to find an optimum location for a land fill site. There are various parameters I need to map. I have managed to map all the ones within a distance of ...
4
votes
1answer
260 views

Calculating Distances between coordinates

I have 75 coordinates in WGS84 that I brought in from an Excel table. They are now on my imagery basemap spanning across about a half mile on either side of a dirt road in Prescott National Forest in ...
6
votes
1answer
120 views

How to group 10k points into closest pairs?

I was first faced with a problem of grouping 1000 pairs into unique pairs to minimise the total distance - since this was a small number I solved it using linear optimisation: Part 1 - Basic/Naive ...
3
votes
1answer
56 views

Vincenty or (Project + Euclidean) for accurate distances

I posted a similar question on stackoverflow, however was directed here for more help. If my main goal was to calculate distances such that my error was minimised to the nearest metre assuming that ...
1
vote
1answer
32 views

QGIS: Distance Matrix tool omitting some points in output table. (qGIS 2.10.1-Pisa)

I have used the Analysis Tools -> Distance matrix to merge two datasets by the closest points. But in my output csv file, some of my points are left out. In the original datasets, none of these points ...
6
votes
3answers
694 views

Network distance computations using GRASS

I'm an ArcGIS user who's interested in learning to use GRASS. Can anyone point out resources that will help me in learning how to obtain network distances between (1) residential locations (points) ...