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

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7
votes
1answer
616 views

What is difference between ST_DWithin and ST_Distance for proximity search in PostGIS?

I have records stored in a table with latitude/longitude coordinates stored in a geometry field. I want to find all records nearby a user supplied reference point. Note "nearby" probably means less ...
0
votes
0answers
27 views

PostGis: find distance if closer than X. For huge sets [duplicate]

I have two tables (that can have different geometry: point, line, polygons, ecc...) and I have to find distances: for all features in table A, for all features in table B, if feature is closer ...
1
vote
1answer
31 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 ...
1
vote
1answer
28 views

ERROR 000989 Issue with Python Script and Field Calculating distance between two long lat points

very new to scripting and I have been struggling with my script for a while. I'm not sure why it doesn't work in field calculator. I am trying to calculate a list of distance between two long lat ...
2
votes
2answers
76 views

Measuring distance between two points?

I have two shapefiles and I would like to know the distance between each point on File1 and each corresponding point on File2 (one to one relationship). I have been using the Ruler and manually ...
1
vote
2answers
87 views

cross track distance to great cicle line and rhumb line

How to calculate cross track distance to great cicle line and rhumb line? For great circle line, I've tried this formula, but it is not accurate while the distance is less than 0.1nm. For rhumb ...
0
votes
0answers
27 views

Finding Cooks Distance on ArcGIS

is there a way to find Cooks distance on ArcGis or do I have to use SPSS?
1
vote
1answer
42 views

Compute nearest points to other points using GRASS

I have a layer of address points and a layer of polling stations. My task is to determine the three closest polling stations to each address on the street network. I think that the answer is in ...
1
vote
1answer
38 views

Creating random location within a network from a given location and a given distance

For a habitat selection study, I am trying to identify availability. My species lives along waterbodies and I could assess distances moved between two consecutive locations using the network analyst ...
1
vote
2answers
53 views

Calculate nearest feature with a barrier

I have three shapefiles: a) polyline with rivers and streams (also as polygon available to me), b) polylines of highways and roads and c) point file with locations in the riparian vegetation. I want ...
2
votes
1answer
56 views

Calculate Height Data From Three Known Points

What's the best way to calculate "height" (snowfall, actually) data from three surrounding locations? For this example, I'm looking to arrive at a "close enough" snowfall value at point A by ...
7
votes
5answers
3k 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 ...
0
votes
0answers
57 views

How to create shape file and show in map using Python?

I have calculated distance between longitude and latitude by import .csv using python. Now I want to show this points or distance between points in map. So how can i do it by using only python? and ...
2
votes
3answers
3k views

How to calculate how long an arc second is for a given long/lat?

I am wondering what area is covered by a dataset which is one arc second wide.
-1
votes
1answer
79 views

Cause of KeyError in Python Toolbox of ArcPy?

This question arises from Performing Point Distance analysis using Basic level license of ArcGIS for Desktop?. I basically copied and pasted PolyGeo's answer and formatted it into a python toolbox ...
1
vote
1answer
38 views

What does st_hausdorffdistance Actually Compare

Does st_hausdorffdistance just look at discreet points used to construct a line segment or does it compare two line segments as a continuous set of points? Also, the points used to construct my line ...
2
votes
1answer
28 views

Adding cost from line shapefile using ArcGIS Network Analyst?

I have a network dataset (a road network), and require a matrix of Cost Distances between many points, which works well. I have now added a line shapefile (representing rail lines). I wish to use it ...
1
vote
0answers
34 views

How can I find which point is furthest from something?

Here is an example of what I am looking to do: Which town in South Dakota is farthest from a Hospital? Which tool would I use to be able to do this?
0
votes
1answer
619 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 ...
1
vote
0answers
16 views

Needing to find parent zip code of a bunch of missing zip codes in the US

We're using MapPoint to export zip code / territory combinations. Unfortunately, the export doesn't include PO Box zip codes which mean that we're missing a lot of zip codes The PO Box zip codes are ...
3
votes
0answers
25 views

QGIS Cross Section Profile Distance using Ellipsoid?

I am working with QGIS 1.8 and 2.6 and can't get any of the Cross Section Profile tools to provide the ellipsoid ("proper") distances. All the distances use geographic coordinates which are too ...
4
votes
2answers
274 views

Best formula for calculating short distances in UTM?

I'm fairly new at calculating distances with precision, but I wanted to know what is the best formula for calculating short distances in UTM coordinates. The distances that I'am calculating are all ...
2
votes
1answer
824 views

How to calculate pixels per meter ratio, according to Google or Bing map zoom level?

I have an image and detect two points in the image. I want to calculate the distance between these two points. I'm using Google map and Bing map. I have x,y pixel values for both two points zoom ...
2
votes
0answers
65 views

QGIS Problem in calculating the distance of points from line

I need to calculate the distance of villages ( villages as points) from a border. I have a shapefile containing the locations of villages and another one containing the border. On QGIS, I ran the ...
2
votes
2answers
52 views

Measuring distances between many points in ArcGIS for Desktop?

So I'm new to this, the answer is probably really simple. I have a point map of X Y data points (one for each participant) for a certain activity. I also have a shape file of zip codes, which I ...
3
votes
1answer
213 views

Shortest distance from polygon centroids to a line in QGIS

To get the distance of each polygon centroid from a line, I have tried the Distance to nearest hub algorithm from the Processing Toolbox. The distances I got from the algorithm did not seem correct, ...
2
votes
2answers
73 views

Flow Mapper wrong line length calculation

I'm finding some trouble with the length calculation in the Flow Mapper plugin. As you can see in the picture below the length of the 2 lines C001-C021 = 4233.7986... C001-C009 = 6069.3053... is ...
5
votes
5answers
3k views

How to calculate distances in a point sequence?

I'm looking for help calculating the distance between a sequence of points that are in a single Shapefile in QGIS. Below is what my data look like and a blank distance column I've added to show how ...
3
votes
3answers
6k views

Calculating the minimum distance between points and polygons in QGIS

I have two vector layers: one point and one polygon and I want to calculate the minimum distance of each point from the polygons (ie the distance from the closest point of the closest polygon). Is ...
0
votes
4answers
2k views

Return all results within a 30km radius of a specific lat/long point?

I have a table with a column the_geom which contains data similar to: ...
2
votes
1answer
61 views

Distance between consecutive points

I am wondering how I can get the distance between consecutive GPS locations in ArcMap 10 (i.e. the distance between consecutive GPS locations sent in during a wildlife telemetry study).
2
votes
1answer
176 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
votes
0answers
25 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
56 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
68 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
387 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
84 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
613 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
139 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
87 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
62 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
828 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
89 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
67 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
101 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
101 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 ...