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Questions tagged [nearest-neighbor]

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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Error creating DEM with Nearest Neighbour tool in QGIS?

I have an issue when I am creating a DEM with the tool natural neighbour on QGIS. When I extract my data directly on Qgis I have no issue creating a DEM. My points are coming from different sources ...
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38 views

Nearest Neighbor - return object ID in R

I have a csv file that contains the GPS coordinates of about 100 villages and their unique ID. I have an other csv file with the GPS coordinates of some potential destinations and their unique ID. I ...
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Seeking package/function in R that can help tag GPS coordinates of fauna sightings to nearest sampling point?

I have 1 dataset of animals sighted walking a survey, and I would like to tag them to the respective sampling points along a transect. Any idea what function/package in R can do that? Maybe ...
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351 views

Nearest Neighbor Analysis Results

I'm fairly new and entirely self-taught in using QGIS 3.4. I'm looking at turtle nest sites and trying to run a nearest neighbor analysis to analyze their distribution and establish whether or not ...
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175 views

Geo-hash finding nearest neighbour with massively variable distance to actual nearest neighbour

I have a series of points in lat-long space, ranging from having their nearest neighbour very close to 1000s of km away. Say I do a geo-hash of these to a high precision, my search of nearest ...
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156 views

Find the nearest neighbour for points in one layer to points in another, then measure the distance

USING QGIS 2.18.19 with python console (planning to upgrade to the newest QGIS after this piece of programming) I am struggling with finding the correct pyQGIS coding for this. I have a shapefile ...
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90 views

create neighborhood list in R with large dataset

I want to create a weight matrix based on distance. My code for the moment looks as follows and functions for a smaller sample of the data. However, with the large dataset (569424 individuals in 24077 ...
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137 views

k nearest neighbour with count limit

I have a set a points, and I want to create 10 clusters. I used attribute based clustering plugin, which worked well for creating the clusters, but the points count isn't perfect, some clusters have ...
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173 views

Finding the closest points to a line with only one point from each subset of points

I have a set of data points that represent many paths for different journeys, where each journey has its own identifier (Operation No). The data for all journeys is in a single table but in effect has ...
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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 ...
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97 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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622 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 ...
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297 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 ...
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462 views

Can Nearest Neighbor Analysis help determine values for a Heat Map?

Given the below parameters (from Nearest Neighbor Analysis): A) Is there a definite range my Radius value should be within? B) Are there definite values my cell size should be near? C) Is there a ...
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Nearest Neighbour Analysis Or NN join

I have two Layer in my Project 1) Voronoi Layer which is constructed on point Layer 2) Building Layers which is represented as Polygon. The goal is to find the nearest node for every polygon (...
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249 views

QGIS Nearest Neighbor Analysis on Layer Subsets with User Defined Area

I have a data set of developments of various types in a single US City. My aim is to run a nearest neighbor analysis for each of the various development types to explore how clustered, random or ...
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576 views

NNJoin returns incorrect distances

Bottom Line Issue: The distances I get from NNJoin for the shortest distance from a point to the nearest polygon are several hundreds or even thousands of meters shorter than the distance I calculate ...
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45 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
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Applying Edge Correction in ArcGIS Average Nearest Neighbor?

I am using ArcGIS 10.3 with the tool Average Nearest Neighbor from the Spatial Statistics toolbox to describe the data. I want to avoid mistakes caused by Edge Effect. In the Ripleys K Function tool ...
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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 ...
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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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585 views

Using spatial index in spatialite query?

I posted this question originally Using nearest neighbor query in SpatiaLite? Using the answer given I was able to get the query working on some test data. However I am having trouble applying a ...
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127 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 ...
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627 views

Loop though records in PostGIS (using PL/PYTHON or PGSQL)

I've seen many example of loops, but I can't get that one to work. I work for a regional transit agency and each year, we conduct several surveys. I geocode everything to the house level for internal ...
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NearestNeighbor producing bad quality tiles

I have been using Bicubic interpolation to render some basemaps because this produced good results. This is what I get when using Bicubic: However, when using Nearest Neighbor interpolation, a white ...
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31 views

Finding nearest 10 observations that occurred 2 years before original observation using ArcGIS Pro ModelBuilder?

I have a point sample of house sales (~42k points over 9 year period) with a date field(integer), and for each point I want to find the 10 nearest houses within a year of sale and also which were sold ...
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PostGIS - Nearest Neighbour Join to sum values

I have a table of polygons T1 and a second table of points P1 Each point has a value I want to sum the values of P1 for each T1, with P1 being the closest set of points to T1 At the moment the only ...
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58 views

Sampling Points and Areas around them

I have some coordinates in QGIS. I want to sample the values corresponding to those coordinates on a layer. I know that I can do that for the exact point using 'Point Sampling Tool'. Is there also a ...