A technique for resampling raster data in which the value of each cell in an output raster is calculated using the value of the nearest cell in an input raster.

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13 views

max sum within a 200mt radius

I have a SpatialPointData Frame in R. Each point represents lat long and InsuredValue amount. I would like to find the maximum sum of insured value in a radius of 200 mt. How I can do in R
4
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1answer
64 views

Calculating distance between points of the same layer

I am using QGIS 2.13 and a layer with hundreds of points. I need to calculate the distance to the nearest point... in the same layer. I tried the distance matrix but I get 0m since the "closest" point ...
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1answer
228 views

Saving samples in eCognition

In eCognition developer is it possible to save samples that I have selected for nearest neighbor classification with the workspace or project? Every time I close and reopen my project I have to re ...
2
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1answer
41 views

Nearest neighbors

I have a point shapefile overlayed over a grid-based polygon shapefile. I would like to select the nearest neighbor grid cells of a given grid cell that contains any of the given point(s). So let's ...
2
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1answer
772 views

Distance to nearest point for every point same SpatialPointsDataFrame in R

I have a SpatialPointsDataFrame that I'm working with in R. I want to add a new vector to the dataframe that contains, for every point, the distance to the nearest other point in the ...
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1answer
46 views

Finding nearest point using point dataset using QGIS?

I have created Geocode for some area and I couldn't find accurate Geocode's for few address. so I want to find the nearest POI for non accurated locations using accurated geocodes as referece in QGIS. ...
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1answer
60 views

Optimizing PostGIS k-nearest neighbour function for large amount of polygons?

I created a function for identifying the K nearest neighbours for every municipality, which works fine, but when I use this function for a large amount of municipalities (over 2900) it takes over 2 ...
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1answer
41 views

Finding neighbors for non adjacent polygons in R [closed]

I'm looking for a method or function in r-project that create a neighborhood matrix from a group of polygons that don't touch each other, like polygons of set of blocks separated by streets in a town. ...
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0answers
34 views

Points within a circle in Python - geoindex

I'm trying to use the geoindex package to perform a nearest neighbor query. For example, I have this two coordinates (in the real case I have a lot more): (40.607255, -73.75083) (40.7261465 -73....
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2answers
749 views

(Smooth) Isoline Extraction from TIN - Algorithms

Can anyone point me to a clear document or algorithm for extracting smooth isolines from a Triangular Irregular Network? I've seen some examples using the jagged linear methods, but can't seem to ...
2
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1answer
38 views

Average Nearest Neighbor does not have all the options

I have a point feature class that I used the Average Nearest Neighbor from the ArcGIS software to calculate the pattern. ArcGIS produces output chart that says whether the data is dispersed, random ...
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1answer
36 views

Nearest Neighbor Analysis for route events

I have events that are on routes. You can think of it as accidents on a highway. I want to do some spatial statistics on it. The road is an M enabled feature class and decision makers want logical ...
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1answer
24 views

Average Nearest Neighbor tool extreme restuls for different area?

I'm using the "Average Nearest Neighbor" tool in ArcGIS 10.3 to calculate whether my point feature class is clustered, random or dispersed. One of the parameters is area. I tried putting different ...
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0answers
13 views

How to apply Edge Correction in ArcGIS Average Nearest Neighbor

I am using ArcGIS 10.3 with the tool Average Nearest Neighbor to describe the data. I want to avoid mistakes caused by Edge Effect. In the Ripleys K Function tool there is an option to control that (...
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0answers
15 views

When would I use K analysis over NNA?

I'm working with the dataset Redwood (62 redwood trees in a 23^2m square). I intend to test whether these are random or not. In what cases would I prefer Nearest Neighbor Analysis and in what cases ...
13
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6answers
911 views

PostGIS: Assign ID of point in layer A to closest point in Layer B

This should have been an obvious precursor (that I didn't ask) to my other question: PostGIS function to create spider diagrams? If I do not know the relationship between a point in layer A (stores) ...
3
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1answer
59 views

Nearest neighbor analysis, write multiple columns to table

I have a table (table1) containing 800 points that I want to join with a table (table2) containing only 10 points. The idea is that the points in table2 are assigned to the points in table 1 based on ...
2
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0answers
35 views

Setting vector area

I'm new to QGIS and am using it to spatially analyze the placements of artifacts within an excavated site. I am trying to conduct nearest neighbour analysis; however, I do not know how to set the area ...
3
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1answer
251 views

What algorithm does QGIS use to calculate Nearest Neighbor Index?

I'm carrying out nearest neighbor analysis on a set of geological features in QGIS, trying to find out whether they're clustered or not. I've calculated the nearest neighbor distances using the '...
3
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0answers
46 views

Choosing interpolation method for monthly atmospheric parameters derived from AQUA/Air satellite?

I want to investigate atmospheric refraction and i am using Aqua/ Airs satellite data. These are atmospheric parameters (1) Air temperature (2) Geopotential height (3) Relative Humidity All these ...
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1answer
1k views

How to find nearest city using Geonames features codes

I've got about 300,000 lat/lng coordinates of events that I'm combining into a large map. The coordinates come from all over the world. For each point, I want to find the nearest city of at least XYZ ...
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1answer
95 views

Nearest Neighbour function

I'm trying to create a function which calculates the nearest neighbors under a certain length in a table s_1 an stores them in an output table. This is what I've got so far: CREATE OR REPLACE ...
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0answers
32 views

Grid resolution and distance upper bound in nearest neighbor

I wrote a routine to interpolate values of GRIB files (coming with several grid types like regular, reduced and rotated) to a target grid, using scipy KDTree to find indexes and distances. Since ...
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0answers
37 views

Coordinate System choice for Nearest Neighbor

Here's an interesting scenario I came upon yesterday and I wanted to throw it out as a question to try help me visualize what is happening. I have a single point (a person, say) who is looking for ...
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3answers
2k views

Optimize nearest neighbor query on 70 million point cloud on SQL Server 2008

I have about 75 million records in a SQL Server 2008 R2 Express database. Each is a lat long corresponding to some value. The table has geography column. I am trying to find one nearest neighbor for a ...
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1answer
29 views

Append near tables, error message

I have 50 near tables that I want to append, so I can export them at once. However, when I use the append tool an error comes up saying that the near tables are 'read only'. Is there anyway to make ...
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2answers
462 views

How to create a line between a point and nearest neighbour using python (template included)

I have 2 shapefiles - one is a series of points, the other is a polyline. I want to draw a straight line between each point to the nearest point on the polyline. This question has already been asked ...
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1answer
73 views

Get all streets within a certain radius with osm2po

I'm trying to get all street segments out of osm2po graph, given a geo point and a certain radius. Right now I just do a breadth first search out of the street that's closest to my point, but is there ...
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0answers
125 views

how to use spatial index in spatialite query

I posted this question originally nearest neighbor query in SpatiaLite. Thanks to the answer given I was able to get the query working on some test data. However I am having trouble applying a spatial ...
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1answer
441 views

nearest neighbor query in SpatiaLite

I am trying to find the nearest line to each point in a layer, and I have over 1 million points. I want to be able to associated the closest unique line ID with the point unique IDs. I have tried to ...
6
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1answer
689 views

Stats on individual grid points nearest neighbours

I have shp of points where each point is the centroid of the individual cells of a 1*1km grid (~ 500 000 points). For each of these points, I have their coordinates and elevation. What I want: for ...
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1answer
97 views

Number of Neighbors Around a Point

I need to get a count of neighbors within 100m for each point in a set of 250 million points. The result would have the id of each point accompanied by the number of neighbors around them. Can this be ...
2
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2answers
423 views

nearest neighbor with postGIS and nodejs

I'm using postgreSQL 9.1 , postGIS 2.0, nodejs 0.10.12 and the latest version of node's pg module. I use websockets on the server side. I implemented a function that tries to find the 5 nearest ...
3
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1answer
607 views

How to calculate the distance to multiple locations from each cell of my raster?

I'm working with Arcgis 10.1 and Python 2.7.2 How can I calculate the distance to multiple locations from each cell of my raster? I tried euclidean distance but it only provides the distance to ...
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2answers
2k views

Calculate Distance between a Polygon and a Point Along a Path

I am very new to ArcGis and am trying to figure out how to do this. Basically, this is what I am trying to do: I have a map of Canada and in it I have polygons representing areas (each about the ...
1
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0answers
70 views

Why would Nearest Neighbor Analysis give 0 observed mean distance?

I am working with small datasets (around 100 points or less) with Nearest Neighbor Analysis in QGIS 2.8 (although I also tested in 2.6 and the result is the same). I have the layers referenced with a ...
0
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2answers
160 views

Neighbors within distance from every row

I have a research project of 180,000 entries and I need to calculate the number of neighbors (points from the same table) that exist within a 300 meter radius for each point. My method is very slow, ...
9
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2answers
5k views

PostGIS nearest point with ST_Distance

I need to obtain on each element on one table the closest point of another table. The first table contains traffic signs and the second one the Entrance Halls of the town. The thing is that I can't ...
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1answer
82 views

KeyError: u'M' in Average Nearest Neighbour test

When I try and run the Average Nearest Neighbour test on my Shapefile I get the error: KeyError: u'M' Failed to Execute (AverageNearestNeighbour) On a "normal" Shapefile this works fine. However I'...
2
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0answers
317 views

N Nearest Neighbours efficiently PostGIS/Python

The data is worldwide about a million points, lat/lons, with an id and an importance value (0.0 to 1.0), and it's limited to being on land. Ideally I need to cluster all 1 million points into 100,000 ...
4
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1answer
132 views

Spatial Analysis - Identifying Regions with Common Boundaries

I have the shape file for DC PSA's as defined in 2012 (see below). I would like to be able to identify in semi-automatic fashion which PSA's are neighbors - that is, which PSA's are nearest neighbors ...
3
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1answer
174 views

PostGIS Nearest Neighbour outside buffer

I am trying to find the 6 nearest neighbours to a point which are outside a defined buffer. Basically I am comparing points of the same table and working with Mike Gleason's examples. WITH subq AS ...
3
votes
1answer
475 views

QGIS - Calculate distance between a point layer to n nearest polylines

In QGIS I am trying to calculate the distance from a point layer to a polyline layer for the n nearest polylines. I have figured out how to calculate this distance to the centroid of the polylines ...
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1answer
616 views

Generate Near Table and keep all attributes

I am trying to calculate the angle and distance of points to surrounding polygons. The table is good and what I need but it doesn't maintain all records; the unique point and polygon IDs are not there....
2
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0answers
134 views

Weighting Point Data whilst performing a Near analysis

I am struggling to work out how I can assign weights to my points (airports), So far I have carried out a Near fuction so that all of my raster (output areas ) are assigned a point with its distance ...
1
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1answer
137 views

Remove points within x distance

I have these spatial points: long <- c(-1.769717, -1.767766, -1.769170, -1.768462, -1.768389) lat <- c(54.92214, 54.92207, 54.92113, 54.92167, 54.92165) points <- data.frame(long, lat) ...
13
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3answers
3k views

How does Nearest Neighbor Image Resampling work in ArcGIS?

I am trying to understand how nearest neighbor for the resampling of Image datasets works in ArcGIS. The output raster cell value is the value of the closest cell value in the input raster: In this ...
1
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1answer
282 views

Finding closest Intersection between line strings (PostGIS)

I want to find the distance between one point (excavation sites) and a line (rivers) for the cardinal directions. What I thought would be the easiest way is to draw lines between the excavation site ...
6
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2answers
651 views

Calculating spatial lags per year in R

At the moment I am having some difficulties with calculating a spatial lag in R. I know how to calculate the lag in space-wide format but am unable to do it in long form, i.e. have repeated ...
3
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1answer
2k views

Improve speed of PostGIS “nearest neighbor” query?

One of the features of the Python/Django/PostgreSQL web application I'm building is that a user will be able to see the 100 other users who are nearest to them, sorted by distance. I'm using PostGIS ...