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Questions tagged [spatial-statistics]

The field of study concerning statistical methods that use space and spatial relationships (such as distance, area, volume, length, height, orientation, centrality and/or other spatial characteristics of data) directly in their mathematical computations.

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Using raster stack function time in R?

I successfully ran a function over a smaller test raster stack (48 layers) in about 30 minutes but cannot run it over my large stack (1462 layers). The last one I tried over the large stack ran from ...
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2answers
69 views

Heuristic relationship between number of satellites and GPS precision?

I'm a statistician conducting an analysis on animal movement based on data collected using ATS Wildlink 500 collars. As part of this analysis, I'm estimating GPS error assuming that the error in the ...
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57 views

Reducing “noise” in spatially regressed points

I'm working on spatial data on a grid. I have two variables that I think to be correlated and I would like to build a model (see Fig attached). I did some exploratory analyses following the ...
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1answer
62 views

How kriging variance is calculated in R gstat?

How does exactly the krige function (a wrapper to gstat and predict functions) from package gstat calculate kriging variance (minimized estimation variance) in Ordinary Kriging? I wanted to reproduce ...
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27 views

Why in Qgis the method “Zonal Statistics” is faster than when I run the method from the command line?

When I execute the Zonal Statistics algorithm, according to the official website, the creation of the output files becomes slower than when the procedure is performed by the own program. I would be ...
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47 views

Estimate spatial kernel density from raster and output kernel values in a grid

I would like to use a raster map (find below) to estimate or create a kernel density distribution. The objective is to extrapolate the kernel density function and re-use it in order to distribute a ...
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20 views

Method to spatially analyse and compare sets of points with eachother

I have 3 sets of points represented by the image below (3 different shapefiles). Each point has a coordinate. All points represent the same type of real world feature (veterinary surgeries) Using ...
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1answer
41 views

Standard deviation for percentiles interval in Google Earth Engine

I'm working on a GEE script aiming to extract DEM-based elevation statistics for regions defined by polygons. Specifically, I want to obtain the mean, median, standard deviation, and min/max values of ...
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1answer
30 views

How to create two Windows in spatstat for the same dataset?

Spatial patterns: I have a dataset of coordinates and marks (diameter) attributed to the points. I am trying to create a window (owin()) for each plot (I have 2 plots), but I don't know how to set the ...
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47 views

Error in calculating covariance matrix and fitting variogram model

When constructing variogram model, usually the spatial points are given, and we build a variogram model and conduct parameter estimation. But here in my question the points are not given while ...
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1answer
39 views

Mismatch in area calculation using R and ArcMap?

I am new to spatial statistics using R. In this scenario, I am trying to calculate the polygons area with in a shapefile by usingrgeos::gArea and compared with ArcMap calculate geometry value. both ...
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22 views

Rasterizing/Building Overlays in R?

I'm currently attempting to build a grid-like dataset in R based of census data (at the block or block group level, but I imagine the method would be same for any level of granularity). My initial ...
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35 views

Statistical analysis of polygons QGIS : find areas of statistical difference

I have polygons for the country divided into E.D. areas. These polygons illustrate the average annual rainfall in their ED area. Is there any way to statistically tell if one polygon area has a ...
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1answer
87 views

Cokriging: zero distance cross-semivariance in undersampled cases [gstat error]

Trying to cokrige two variables that are not perfectly colocated (one has sparser measurements than the other), I faced an issue that I'll illustrate with the following MRE. With the meuse dataset, ...
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1answer
28 views

Install GRASS GIS extension r.pi including r.pi.prox and implement the Addon in QGIS

I would like to install the GRASS GIS addon r.pi within QGIS, I only have access to basic GRASS commands I installed QGIS using the osgeo4w-setup-x86_64.exe advanced installation using the http://...
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1answer
34 views

How can / should sf spatial objects be translated (i.e. moved within same projection)?

Big fan of the sf (and previously, sp) spatial packages in R. I see spTransform and st_transform as methods to reproject a spatial object into a new space. However, I have a case where I have a ...
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0answers
45 views

Any advantage to use elongated focal window for raster Pearson's Correlation?

I am performing Pearson's Correlation with 2 rasters (same res, size, extent), and will use a focal window, but is there any advantage or robustness to using a focal window that better reflects the ...
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1answer
126 views

What is a relevant geospatial modelling approach when no spatial autocorrelation is found?

Although I have found on StackOverflow all answers I ever had on GIS matters using R, ArcGIS and QGIS in the past, I am currently faced with one question I can't find an answer to online. For my ...
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1answer
70 views

Moran's I: Selecting the best option for conceptualizing the spatial relationship between # births & county locations

I'm using Moran's I to see whether there are clusters of births rates present among the 83 Michigan counties, and, if so, whether the clustering is statistically significant. The inputs are the ...
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0answers
19 views

Subsampling data to reduce autocorrelation/pseudo-replication

I am interested in the effect subsampling data has on reducing autocorrelation/pseudo-replication. My application is biologically-inspired: I am examining trends in genetic variation within species ...
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1answer
36 views

LecoS batch processing - Is there an easier way?

I'm using the LecoS software: https://github.com/Martin-Jung/LecoS I've clipped my raster to reduce processing time to focus in on the areas I'm interested in. The entire raster has 11 classes, but ...
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0answers
44 views

How to calculate sum of values in a point shapefile within a moving window

I have a point shapefile that has a 'rank' attribute with numbers between 0-100. I need to calculate the sum of this value for points within a 10km circular moving window anywhere within my area of ...
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40 views

Calculating Moran's I on large point dataframe in R

I have a dataset of about 77,000 points of which I want to test autocorrelation. I have tried to compute the test statistic using the testSpatialAutocorrelation tool in the DHARMa package, which uses "...
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43 views

Points to a 1km x 1km cell grid

I have a large database of point data throughout all of Eastern Australia. Each point represents species presence/absence data and has attached about 18 predictor variables. To account for sampling ...
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1answer
56 views

correlation matrix and p-value in grass

I'd like to know if there is a way to obtain statistical significance and p-value for correlation coefficients calculated for different raster in grass with the command r.covar All that I obtain is ...
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1answer
103 views

Is there a statistical test to calculate difference/similarity between two sets of lat/lng data points?

I have two sets of data points where each data point is a latitude-longitude combination. The two sets represent two different time frames, let's say 2010-2014 and 2015-2018. The number of data points ...
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24 views

Visualizing two different datasets amicably when they are measuring two different things

I am working on a story map in AGOL that is comparing the percentage of a population that lives in a house that has been deemed transit dependent versus the concentration of a population that lives in ...
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0answers
10 views

test.W ade4 package FUNCTION NOT FOUND

I am trying to perform a MEM analyses, Morans eigenvectors spatial analyses, test.W function Selects among the MEM variables constructed on Delaunay Triangulation I am trying to use the function test....
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1answer
72 views

How do you find the appropriate spatial weight to use for a spatial analysis? [closed]

I am currently about to run a spatial regression (OLS, Lag, Error etc) for my dataset. My dataset contains 1000 randomly generated points throughout the utilisation distribution for my animals (so, ...
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1answer
190 views

How to extract specific values with point coordinates from Kriging interpolations made in R?

By using R version 3.4.2 and the library "geoR", I made kriging interpolations for different variables (bellow I give an example of my process). I also made a matrix with the coordinates for 305 trees ...
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1answer
67 views

Is there a tool in ArcToolbox that can compare types of shapefiles?

I have a some point shapefiles that represent categories of folklore story, witch, mermaid etc. I also have some point shapefiles of landmarks like portal dolmens, ancient woods etc. Is there a tool ...
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32 views

How to assess significant land cover changes using Chi-square test?

I have a series of land use maps at different times as a result of a classification process on Landsat images. I am mapping 3 different thematic classes : bare soils, vegetation and croplands. I ...
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1answer
52 views

Return Majority from PostGIS function ST_SummaryStatsAgg()

The mentioned function Returns summarystats consisting of count, sum, mean, stddev, min, max for a given raster band of a raster or raster coverage. I have an image of land cover classes (a ...
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1answer
33 views

Using modeled surfaces together to make predictions?

My question is about stacking multiple rasters of predicted surfaces, that have some of the same predictors. For example, if I make a predicted surface using all the terrain attributes as ...
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1answer
89 views

How to estimate the standard error on the mean difference between two DEMs?

I have two DEMs of the same area measured on two different dates. Differencing these DEMs gives a map of the change in height between these two dates. I would like to calculate the mean change in ...
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1answer
32 views

Kriging: Large standard error very close to known value points

I am attempting to create surfaces of strata via Kriging in Arc GIS from borehole data. In addition to the predicted surface I also want surfaces showing 95% confidence above and below the predicted ...
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30 views

ArcGIS: Get coverage of Polygon A in Polygon B

We have dissemination area (DA) units for a city [Polygon B], and shapefiles of all parks in the city [Polygon A].Polygon A overlaps Polygon B in some areas. We initially wanted to calculate the ...
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0answers
51 views

Reclassify land use map based on agricultural statistics [closed]

I'd like to create a land cover map of Greece with enhanced information on the spatial distribution of agricultural crops. As you know, common land cover products (such as ESA CCI LandCover or CORINE)...
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21 views

Comparing Point and Polygon Datasets Statistically?

I have two datasets, one contains a set of points detailing the home locations of a series of individuals, the other dataset is a fishnet grid of polygons within each cell is contained the number of ...
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0answers
59 views

How should I normalize my data - based on population of an area /neighbourhood or population of the entire city? [closed]

I am studying the driving's forces of crime in a particular city. I have some independent values, e.g. percentage of the head of the household with low education per zone, the percentage of ...
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2answers
133 views

Getting the average of maximum values from raster (tree top segementation)

I've got raster with elevations of trees in a forest. I would like to find out the average tree height of all trees in a given area. Because of the geometry of a tree top (which is like a cone and ...
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0answers
30 views

Spatial statistics for points in polygons ArcGIS

I have a dataset where I've spatially joined points to a set of geology polygons and produced a count per polygon. I now want to run statistics to test whether these points occur more frequently in ...
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1answer
60 views

R visualization of the correlation of a point distribution to the attributes of the polygons they are located in

Situation: I have two spatial data frames, one of type polygon (areas with different average wind speed levels) and one of type point (wind mills). I read the polygon shapefile with readOGR, the ...
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0answers
46 views

Spatial Downscaling of global temperature in R?

I am interested in spatial downscaling of global temperature to grid cell. What I have is a vector of future annual global temperature values which I would like to downscale to (hopefully) 0.5°. ...
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0answers
166 views

How to create raster from data (x,y,z in Cartesian coordinate System)?

I have simulated many trajectories of an moving object. From simulations I have obtained data files where the trajectory is saved in terms of x,y,z coordinates recorded at equal time intervals. Each ...
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1answer
50 views

Expression Area Statistic Results in NULL with Real Number Conversion

I am attempting to determine the ratio of a statistic to the area of corresponding geometry while accounting for outliers through a standard deviation filter. While the QGIS Expression Editor ...
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1answer
48 views

How to specify the polygon in which to generate points when using the Kenv.csr() function in R?

I would like to use the Kenv.csr() function, out of the splancs package, which computes envelope of Khat from simulations of complete spatial randomness. My main issue is with one of the parameters: ...
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1answer
399 views

Choosing value of Moran's I to say existence of spatial correlation?

I am a GIS beginner. Usually we use Moran's I to evaluate spatial autocorrelation. Everyone knows the Moran's I coefficient ranges from -1 (uniform) to 1 (clustering); I = 0 means no correlation. If ...
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1answer
57 views

Calculating expected number of points within polygons of different size under hypothesis of random distribution?

Let's imagine we have some polygons that cover a whole study plot (see attached picture). Further, we have some points (red dots) lying within the polygons. For each polygon we want to calculate the ...
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71 views

FRAGSTATS Problem with “User Defined Tiles”

I have had recurring problems using FRAGSTATS 4.2.1 when trying to calculate four land cover classes over a large area using census tracts as the user-defined tiles. I have made sure the two layers I ...