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

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38 views

How to calculate the shortest path to pass on 7.000 UTM points?

Anyone can give me an advice how to calculate the shortest path with a lot of UTM points? In total I have 7000 points, but it can be grouping 100 or 500. I have knowledges about Java and Python for ...
1
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2answers
691 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 ...
0
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0answers
110 views

How to choose data type and SRID, for coordinates from different sources, in a medium size zone

I'm developing an application. In the database I need to store coordinates for many places, in the north-east of Italy, but the area could expand in the future. This coordinates will come from some ...
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5answers
9k views

How to cluster spatial data in R?

I am very new to R, so please bear with me : > 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 ...
8
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4answers
1k views

Looking for a fast, open-source raster cost-distance function to use in code

I've been scouring the internet for a fast, open-source cost-distance function that I can embed inside my code. The functionality should basically work like the ArcGIS implementation where I can ...
3
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4answers
2k 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 ...
3
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2answers
862 views

Total great circle distance along a path of points (PostGIS)

I am looking for an SQL query that sums the distances between a series of points using PostGIS. The situation is as follows: I have 2 tables: tracks and points. Points belong to a track and thus ...
8
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1answer
1k views

PostGIS - Calculate progressive distance between points on a GPX path

I am attempting to build an elevation profile using PostGIS-PostgreSQL only. I have imported GPX data in my PostGis database, so now I have a table full of the GPS coordinates of the track and the ...
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2answers
1k views

Surface distance on DEM between two coordinates

Given two coordinates on a digital elevation model (DEM), how do I compute the actual distance traveled between the two locations, assuming a straight line route? How will changing the resolution of ...
9
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1answer
1k views

Analysing movement using cost surfaces with ArcGIS Path Distance tool?

I would like to analyse hypothetical movement (on foot) in a landscape as based on energy expenditure, but I have run into some trouble that I am hoping that you could help me with. I have tried to do ...
8
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3answers
718 views

Identification of consecutive points within a specified buffer

I have a point file, hourly relocations of an animal, and I want to be able to place a buffer around each point and calculate the number of subsequent points which are within the buffer zone. I am ...
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5answers
4k views

Calculate distance in km to nearest points (given in lat/long) using ArcGIS DEsktop and/or R?

I have two point datasets in ArcGIS, both of which are given in WGS84 lat/lon co-ordinates and the points are spread across the whole world. I would like to find the nearest point in Dataset A to each ...
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3answers
548 views

Draw line between points from multiple datasets

I have 2 point datasets and want a tool or script to draw a line between all points in one dataset to all the points in the 2nd dataset. Is it possible? I have tried ESRI "Point Distance" and ...
9
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2answers
3k views

Measuring distance in spherical Mercator vs zoned UTM

I've got points in WGS84 lat/long and I'd like to measure "small" (less than say 5km) distances between them. I can use the haversine formula from http://www.movable-type.co.uk/scripts/latlong.html ...
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2answers
1k views

How do I group near points with GPS positions?

I'm an IT person so I don't know too much about projections and so on, I hope you can help me. I have made an application for Android that collects a GPS position, so I have the latitude and the ...
7
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2answers
548 views

Projections appropriate for global analysis that preserve area and that preserve distance (but not necessarily in the same projection)

I am looking for a projection (or a set of projections) that decently preserve distances so that I can buffer every country in the world and have a similar level of minimal distortion for each. I ...
7
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3answers
235 views

What's a term for Sea Level Distance which is usable by novice users?

I've been using the term Sea Level Distance to describe the total length of a line string where I ignore the elevation and just calculate the distance from point to point along the ellipsoid and sum ...
6
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2answers
968 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 ...
5
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2answers
4k views

java vividsolutions jts wgs-84 distance to meters

my (java) project uses com.vividsolutions.jts.geom, which provides a distance function. After some googling I finally found that the return value from this function is in central angle degrees, when ...
4
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1answer
561 views

Correct use of the terms geographic, path, and Euclidean distance

I often use the terms geographic and Euclidean distance interchangeably when referring to the length of the shortest straight-line distance between two points on a map. Is this correct? I use the ...
4
votes
1answer
695 views

How to use/interpret/visualise a distance matrix with unknown coordinates?

How would you go about using a distance matrix where points have no coordinates, i.e. what useful statistics can be made and how to visualise it in some useful way?
3
votes
2answers
254 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 ...
2
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1answer
227 views

Finding and using data on population density files

I'm attempting to replicate this map for the state of Nevada in QGIS: source: http://www.bostonfed.org/commdev/c&b/2014/spring/map-distance-to-closest-snap-outlet.htm (A SNAP outlet is just a ...
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3answers
552 views

Toblers's Hiking Equation and Slope Dilemma

I'm trying to use Toblers's Hiking equation to determine economical backgrounds of some hillforts. The equation is anisotropic which means that the speed of movement that it calculates differs whether ...
2
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1answer
675 views

How to Determine to world map size in pixel given this data?

How to Determine the world map size in pixels given this data? Map size of a particular area say, for example: Makati city, Philippines with bounds: Top-Right: 121.0281, 14.56497 Bottom-Left: ...
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0answers
169 views

Is there a tool that tells how many features there are within a set distance in ArcView?

I'm looking to create a raster, in ArcView, that represents how many features (either points or polygons) are within a certain distance from any given location within a study area. I know there must ...
5
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1answer
1k views

Distance Matrix tool in QGIS. How to get result in metric? [closed]

I'm trying to calculate the distance between points in layer with distance matrix tool. And keep getting strange results no matter what. Like this MASTER ------------SLAVE ---------------- DISTANCE ...
4
votes
2answers
118 views

Calculating average raster to point distances within census tracts

I have some experience using ArcGIS, but mostly with the field calculator in the attribute table/spatial joins, so I apologize if I say something that doesn't make sense. To provide a bit of ...
4
votes
1answer
409 views

How to measure the distance of multiple points to a line

I have two shapfile in QGIS to which I am trying to find the distances between. I have a shoreline which is a vector line and then I have hundreds of data points in the ocean. What I am trying to find ...
4
votes
3answers
2k views

Comparing two point shapefiles that contain lat/longs and compute distance using ArcGIS Desktop?

I have 2 sets of point shapefiles in ArcGIS Desktop (group A and B), each set has around 1000 entries that contain lat/long. What I want to do is compare Group A against Group B and figure out for ...
4
votes
2answers
822 views

Plugin for average distance from node to polyline in QGIS?

Is there a plugin available that will calculate this? EDIT 1: The red polyline is the average distance of the point to the black polyline. The red polyline is what I want to display. Alternatively, ...
3
votes
0answers
210 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. ...
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votes
2answers
956 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 ...
2
votes
2answers
181 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 ...
2
votes
0answers
121 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
310 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 ...
2
votes
0answers
199 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
799 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 ...
2
votes
1answer
732 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 ...
2
votes
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 ...
2
votes
1answer
2k 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. ...
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vote
0answers
103 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 ...
1
vote
1answer
87 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
40 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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1answer
206 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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vote
1answer
345 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
457 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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2answers
418 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 ...
1
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1answer
4k views

How to find nearest point for each point in current layer using ArcGIS Desktop?

I have a point layer and want to know the distance of nearest point of current layer for each point in the layer. I found some tools in ArcToolbox about it , but they need two layers for input and ...
0
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2answers
42 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 ...