Questions tagged [spatial]

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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19 views

Variogram of categorial data?

I have a thematic map as raster data with classes assigned as numbers: 1,2,3,4. These are categorial classes and have no linear meaning. I am interested if there is spatial autocorrelation in this ...
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8 views

Spatial lag regression model with significant LM test value: Can we make deductions based on the estimates?

I have a spatial dataset with which I created a "spatial lag regression model". The "Likelihood Ratio test" (LR test) results were significant which means the addition of the lag ...
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29 views

Comparing the overall mean of Monte Carlo simulation runs involving multiple observations

I have a set of n spatial points distributed across the landscape. I have hypothesised that the location of these points is determined by a property of the ...
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6 views

spatstat::plot.envelope observed line longer than significance band [duplicate]

Using the R package spatstat I'm plotting pooled pointwise envelopes of the function Jfox calculated for different point pattern in an hyperframe. The workflow is ...
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99 views

How should I deal with spatial autocorrelation in beta GLMM (glmmTMB)? (Bird diversity)

I am trying to compare certain a taxonomic diversity index (for bird communities) calculated for squares in a map grid system (a total of 34 squares) for two different years: 1998 and 2018. My ...
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1answer
31 views

spatstat::plot.envelope observed line longer than shading

Using the R package spatstat I'm plotting pooled pointwise envelopes of the function Jfox calculated for different point pattern in an hyperframe. The workflow is ...
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15 views

Outlier detection using 2D spatial information

I have a list of sensor measurements for air quality with geo-coordinates, and I would like to implement outlier detection. The list of sensors is relatively small (~50). The air quality can gradually ...
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1answer
169 views

Running a spatial model without having a panel dataset

I am trying to run a linear probability model with spatial lagged Xs in R. The idea is to have the crime_type_1, a binary variable, as the dependent variable, and the faction as the independent ...
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26 views

Evaluating classifier with additional data

I have a data analysis problem where I have a blackbox image processing software that detects certain defects (cracks, potholes, expected objects like manhole covers, foreign objects) on a straight ...
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7 views

Controlling for population in Getis-Ord clustering with varying population density

I'm running a Gi* cluster analysis on population data aggregated into administrative areas. I'm looking for clustering of prevalence of variable A, so I create a ratio based on ...
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42 views

Is there a valid way to spatially disaggregate a country-level time series when data at the desired spatial resolution is available for a single year?

Context 3rd year public health student formulating end-of-year project proposal. Interested in exploring the relationship between economic and health outcomes in a spatially fine panel data setting. ...
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16 views

Clustering geospatial and “ordinary” data

I have big dataset (~100k) of numerical parameters and their locations (lat, lng). What approach should I choose to cluster such data? Usual distance functions won't work in such case and calculating ...
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27 views

Are identical things spatially clustered?

I'm new to working with spatial data, but I am working with a dataset of discrete plant genotypes sampled along a 1-d transect of 30 sampling points, and I would like to quantify the extent to which ...
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30 views

Spatial regression models for counts

I'm trying to model count data with both a Poisson regression model and a Negative binomial model. These counts are referred to the spread of a disease in each spatial unit area (I have 110 obs). I ...
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18 views

Circular variable in spatial GLM / SVM modeling using R [duplicate]

I am modeling spatial data using multiple rasters with the variables shown below. ...
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15 views

spatial autocorrelation in dynamic occupancy models via colext

In biostatistics, spatial autocorrelation can almost always be an issue. In single-season models, one can apply mixed models to take into account spatial cluster of study plots. I wonder whether there ...
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1answer
85 views

Interpretability of tensor product interactions in space

Spatial data (x, y) is most often accompanied by spatial autocorrelation or locally different interactions between x & y. When I want to fit a parameter across space with generalized additive ...
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18 views

Creating a covariance matrix from a distance matrix—normalizing matrix with infinity

I'm trying to simulate spatially autocorrelated data by creating a covariance matrix from a distance matrix and using said covariance matrix as the $\Sigma$ parameter of a multivariate normal. I have ...
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11 views

consider spatial autocorrelation in spatial grid analyses using GLMM

In ecology, spatial autocorrelation is a major issue. When dealing with discrete study plots, these plots can be grouped by their spatial location in order to consider spatial autocorrelation. In a ...
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35 views

Equation for a glmmTMB model with exponential spatial covariance structure

I have read description of the Spatial covariance structure with glmmTMB on this link (https://cran.r-project.org/web/packages/glmmTMB/vignettes/covstruct.html), ...
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17 views

Standard Error or Standard Deviation for error associated with averaging raster values within a polygon?

I am trying to measure uncertainty associated with a mean value for spatial data. I have: A polygon representing a spatial district. A raster dataset that was produced via a Random Forests model, ...
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44 views

Deducing information from a scatterplot

I have two tiff files in R (one modelled and one observed). Both tiffs show the spatial maps of gross primary productivity from 2000-2010. The study area is HinduKush Himalaya (http://rds.icimod.org/...
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26 views

SECR AIC compatibility

I'm a student in ecology and I'm currently doing an internship to validate the first year of my master degree in France. I have to calculate roe deer density for the Mavrovo National Park in Macedonia ...
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9 views

Area and time adjusted counts

In 2019 I went to a site and counted 4 species of birds. The size of the site was 130 hectares and I spent a total of 54 hours counting the birds. The peak counts of the 4 bird species are presented ...
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24 views

How can I determine a gaussian field for thresholding a distribution at each location of a grid?

Suppose $X(u, v) \in R$ is a random variable at location $(u,v)$ of a grid $G \subset R^2$, and $X(u,v)$ can be expectedly decomposed into two components with a unknown threshold $t(u,v)$ with $t(u,v) ...
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11 views

Inconsistent results from partial Mantel test on (non)distance matrices

Currently I am trying to look at the correlation between three matrices of ecological data. All three are forms of distance matrices (two matrices of pairwise community dissimilarities and one matrix ...
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12 views

Selecting a Model for Large-Scale Spatial Monthly Data

I'd like to perform a regression analysis with a large spatial dataset that is likely spatially and temporally correlated. I've described the data, goal, and question in further detail below: Data: ...
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28 views

Sampling Technique: Categorical Data, Many Levels

I have a data set that has a categorical variable with almost half the number of observations as categories. Certain categories have only one observation. A minimal reproducable example in R would ...
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1answer
28 views

What is the “sensible default” for the Kest function of the spatstat package?

I'm reading the documentation on the Kest function (page 731) from the spatstat package. For the argument $r$, that is the "Vector of values for the argument $...
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1answer
29 views

Uniform distribution versus a Poisson homogeneous process with Ripley's K

I'm testing astropy's RipleysKEstimator. I create a 2-dimensional uniform distribution in [0, 1), and obtain its K value for a radius $r=0.5$. It was my ...
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2answers
27 views

Clark-Evans test results contradict to L function results

I have a data set including ~300 points and I would like to see if the point pattern tends to be clustered or not. To do this, I first performed the Clark-Evans test in R: ...
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30 views

(Co)kriging / co-located kriging with heterogenous measurement errors

I have a large set of polygons on a map, some of which contain data on 2 count variables, say ($z_{1}$ and $z_{2}$) that are correlated. In fact, $z_{2}$ most likely causes $z_{1}$ without the ...
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1answer
38 views

Estimating the actual distance by using a series of measurements in between

An object is moving along a single axis, back and forth. We take $N$ snapshots of the object. For all pairs of snapshot positions $i$ and $j$, we can make signed measurements of distance $x_{i,j} = -...
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7 views

Calculating Eta squares for Spatial Models

I am trying to calculate eta squares for spatial model (spatial error, spatial lag, SAR). In simple OLS model we can iteratively calculate explained sum of squared as: $ \sum_{i = 1}^{n} (\hat y - ...
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24 views

Spatial Panel Data Analysis in R: Comparison between 'spml' and 'plm' function

So, I'm a R user and currently working on a spatial analysis on panel data. Based on my experience for these past days, I understand that spml function on ...
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12 views

Testing spatial association between two sets of points (distributed in x-y space between two concentric circles)

I have 2 sets of points that correspond to 2 biological cell types, and these cell types are distributed in x-y space in the region between 2 concentric circles (i.e. an annulus). However, the inner ...
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1answer
27 views

Measures of spatial dispersion

I have a series of data points in R^3. I am considering different measures of the spatial dispersion of these points. I have noticed something interesting. I have considered two different measures ...
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1answer
49 views

model selection for Mixed Poisson model for replicated point pattern analysis

I have fitted a mixed Poisson Point Process Model to Several Point Patterns using the mppm function from the R package spatstat. ...
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13 views

How do you interpret results from crossCorrelation in R from spatialEco package?

I want to use the crossCorrelation function from the R package https://rdrr.io/cran/spatialEco/man/crossCorrelation.html spatialEco to examine the relationship between people's perceptions and the ...
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9 views

Methods to align/reduce distance between two or more 3D graph-spaces?

I'm trying to align multiple graphs of spatial data, similar to image registration, but on a 3D graphspace of a select feature. I have a bunch of point data with x,y,z coordinates that together, ...
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1answer
63 views

Statistical method to quantify the accuracy of point clusters

I have coordinates of about 13 points from different pictures in UTM. Per point I can have 2, 3, 4 or 5 coordinates of these points from 2, 3, 4 or 5 pictures. I would like to quantify the quality of ...
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14 views

How to estimate similarity between new observations and a reference class

I have a large multivariate dataset (derived from a spatial analysis of flood events). The dataset has roughly 4000 observations (locations) each with about 500 site descriptor variables. I know that ...
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27 views

Is this required to cross-validate the results of interpolation?

I have 93 scattered locations rainfall data, I used Matlab scatteredInterpolant function to interpolate these rainfall values to gridded data. The approach that I used is the natural neighbor method. ...
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26 views

Modelling community as random effect based on community-level exposure?

I am conducting community/school research to exploring the health impact of environmental exposures (e.g., air pollution). The exposure is predicted based on the address of the community/school ...
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156 views

How do I make sense of 200 regression models?

I'm dealing with a dataset that has about 300 input features, and about 200 response variables and consists of 25000 samples. These response variables are basically a profile of 200 different values ...
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15 views

How to model “Sparial Variability” or “Choice of Location”

Lets say I have survey data on 10000 delivery-man. I have number of delivery they made in 49 neighborhoods (that is 49 columns plus 01 as "other neighborhoods") and one column as their earning per ...
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10 views

handling spatial auto correlation of case level data in areal units

I'm looking at spatially modelling count data of number of student posts made to an online discussion board for a massive open online course. I have student level data, where the students have ...
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35 views

Reporting Moran's I test results in a paper

I have tested spatial auto-correlation in a generalised linear model using Moran's I test (DHARMa R package). I got results for ...
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18 views

Statistical test for continuous response with multiple levels

I am investigating how the percentage cover of 5 reef species has changed through space and time but I am stuck on which test to use. I have a continuous response variable (% cover) for 5 species of ...
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23 views

Are there spatial (econometric) models to analyze point and area data together

I am learning spatial econometrics. However, I do not feel so comfortable with the idea using spatial areas a unit of analysis, in that I wonder how aggregation to areas can be helpfull except in some ...

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