Tagged Questions

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

140 views

Drawing route on google map using gps device and calculating actual distance?

I Want to draw route on google map with the help of gps device and calculate the actual distance. Can anybody help with this? public GoogleAPIModel GetDistance(string origin, string destination) ...
27 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. ...
118 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. ...
34 views

Discrepancy between CAD and GIS route lengths

I have imported a route from AutoCAD which is marked every kilometre and converted it into a shapefile. I put markers every 100 m using X-Tools. There is a difference between the two sets of markers, ...
66 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 ...
150 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 it'...
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 ...
62 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, ...
40 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 ...
47 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 ...
33 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.
36 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 ...
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 ...
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 ...
62 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 ...
70 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 ...
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. ...
256 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 ...
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 ...
41 views

How analyze reliability of position of new point based on point data

I am working on filter for biogeographical data. It is based on citizen science principle. People put new point data to database and I want add information about "reliability" or probability (maybe ...
264 views

PostGIS get the distance between two points over a linestring

I have a linestring: LINESTRING(-1.3326397 50.9174932,-1.3319842 50.9166939) and I select two points that lay on that linestring. I would like to get the distance between these two points (in ...
72 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 ...
28 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( ...
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 ...
53 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 ...
45 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 ...
26 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 ...
68 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 ...
40 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 ...
138 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 ...
27 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 +...
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 ...
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 ...
68 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 ...
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 ...
62 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 ...
131 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 ...
33 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 ...
62 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 ...
66 views

Why this pyqgis code cause crash dump in QGIS?

In ArcGIS there is gp.EucDirection to calculate Euclidean allocation, distance, and direction around a point, Is there equivalent function in pyqgis or gdal? I wrote a script with help of gene and ...
70 views

Finding distance to closest road (polygon to line) in ArcGIS for Desktop?

For my project I need to find the distance to the nearest road from forest polygons. I'm trying to do a weighted overlay analysis (eventually) for a habitat selection project so I think I need to end ...
72 views

Perpendicular Distance Markers on Polyline in MapInfo?

I have added chainage to a creek polyline in MapInfo v11.0.3 using the 1999 version of "Distance Marker" by Meridian. It looks poor as it does not have the functionality to create the markers ...
114 views

PostGIS Get the POINT that is x meters away from a fixed point on the route (LINESTRING)

We have a route network stored in the routes table (LINESTRINGs). Basically every sedment (between two vertexes) is inserted as a separate row in this table. Among that we have a locations table (...
408 views

Calculate the distance between two coordinates (WGS84) in ETRS89

I have an Excel-file with coordinates (WGS84). From these coordinates I create a line (shp) and transform it (ETRS89). After the transformation I calculate the distance from point to point. I do this ...
46 views

How to create a shapefile from Excel file including coordinates of points and distances between them in ArcGIS?

I wanted to use network analyst in ArcGIS and I have coordinates of points in the network. However, I could not find a shapefile including road information between these points so far (length of links ...
77 views

Getting point from known points to specific distance of polyline using ArcObjects?

I want to know the coordinates of a polyline from specific point and distance. I have attached image to clear the specification. say, I have a points B(2,3). I want to know the coordinates of A and C ...
17 views

Scaling distance by area

For each administrative unit, I calculate the median distance between businesses. However, for larger unit, this distance is naturally bigger (and does not paints a fair picture of, say, the effort by ...
87 views

GeoDjango - save two Point fields, one for geography and one for geometry

Most of the explanations I've read for geography and geometry seem to suggest that one must only use either geometry or geography, and that the only way to use both is to cast/convert between one and ...