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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Orthogonal basis functions in `mgcv`

I have a spatial dataset that I'm modeling using penalized splines from mgcv. Here's a simplified example of what it looks like: For simplicity, I'm modelling some ...
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Model choice - Spatial Binary output [duplicate]

I'm just looking for ideas for this. Say we want to predict the presence of a certain "thing" in a country by each postcode - let's take the UK, so there could be around 1.7 million ...
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Spatial point pattern modelling where the observation of points are uncertain?

I am wondering if there is any literature on this issue. My problem here is not regarding the location uncertainty of the points, it is rather that I am not sure if a point is indeed an event ...
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Spatial change-of-support from coarser areas to smaller, nested areas

I'm working with survey data and for $N$ larger domain units (in this case, spatial) I have an estimate of some response variable $y_i$ and covariate vector $x_i$ for $i\in \{1,...,N\}$. In each of ...
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spatial correlation between two hexa/density maps

I was working on a report and was faced with a question regarding maps and spatial analysis. I want to compare some maps and find the similarities/differences among them. The maps represent the sum of ...
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How to correct spatial autocorrelation with glmmTMB when there are several observations on sites?

I have a large dataset of several species' activity parameters during nights and I want to account for spatial autocorrelation (tests and graphs show that my models suffer from it). However, I cannot ...
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Dealing with outliers when calculating body condition indexes

I am seeking advice on how to deal with outliers when trying to calculate residual body condition indexes (by using the residuals from a regression of body mass with body length). I am using a body ...
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What is an appropriate null model for a GAM with spatial autocorrelation fit using mgcv::gamm?

I am interested in comparing the fits of various general additive models to a dataset with strong spatial autocorrelation using the R package mgcv. There are no ...
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Knowing when to stop with spatial point thinning — is an approach with Clark-Evans test valid?

I need a random sample of presence points from the species' area to use in distribution modeling. I have an excessive amount of spatially clustered presence records, so I use minimum nearest neighbor ...
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Is Nearest Neighbor Distance Ratio (NNDR) test good for assessing point pattern?

Regularity of point pattern is routinely checked in ArcGIS with the Nearest Neighbor Distance Ratio test providing significance estimations: https://pro.arcgis.com/en/pro-app/latest/tool-reference/...
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Compare Moran I at different time periods

Consider the case of X agents distributed in a geographical space. Their number and spatial position is fixed over time. However, their characteristics change from one time to another. I can compute ...
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Spatial Regression using PROC GLIMMIX

I'm experienced using PROC GLIMMIX, but I don't have expertise in spatial analysis. I have data that is at the FIPS (county) level. I'm interested in running a negative binomial regression model using ...
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Nagelkerke pseudo R^2 interpretation in spatial regression

Could anyone explain to me the interpretation of Nagelkerke pseudo R^2 in spatial regression models? Definitions say it is computed using some conditonal probability, but I didn't quite get what they ...
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What distance measure should be used to cluster (A - B) where A and B are correlation matrices?

I have 2 conditions with $m$ variables: Treatment = $X_A$ Reference = $X_B$ I've calculated the pairwise correlation of each condition to have 2 $m x m$ correlation matrices I'm calling: Treatment ...
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min-max-normalized spatiotemporal matrix?

I am using time-series cross-section (TSCS) data and I will like to estimate the following model. $y_{i,t}=\alpha+ \beta \sum_{j=1}^nw_{i,j,t}y_{i,t}+ \varepsilon_{i,t}$ Where $y_{i,t}$ denotes the ...
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1answer
82 views

Conditional posterior distribution of coefficient in logistic regression

I would like to derive the conditional distribution of β in a logistic regression where Y follows a Binomial distribution B(n,p) the probability model is given as: logit(p)=X'β +u+v ; u is spatial ...
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1answer
23 views

Diagnostics of spatial regression residuals in R

I fitted multiple spatial regression models - spatial lag model, spatial error model and spatial durbin model. My question is, how do I check the assumption of normality on errors? In classical linear ...
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1answer
42 views

What algorithm to use to classify image-like data by spatial relations?

Let's assume I have dataset of image-like 2D samples where values can be divided into few discrete levels (for example 1, 2, 3 and 4) like in the image below, where each color maps different value, ...
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1answer
25 views

Testing difference intensity regions of multiple images - GAM?

I am trying to model the difference between the pixel values of two regions in a set of images. Each image is different and contains the pair of regions. My question is about how to take into account ...
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1answer
36 views

Parametrization of the Matérn Covariance Function

For geostatistics problems, I am used to working with the following parametrization for the Matérn covariance function. For a stationary and isotropic Gaussian random field $X(\boldsymbol{s})$, $\...
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Generate data that matches a frequency distribution while preserving the original spatial structure

I am dealing with a 3D array containing values representing the "importance" of each voxel. For my analysis, I would like to synthesize n new arrays from my original array to have a ...
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1answer
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In the R package spANOVA can coordinates be entered directly as Lat/Longs or is a map projection required?

I have some data on fish abundance in a harbour in Canada that I'm analyzing using the R package spANOVA (Spatial ANOVA). I'm using the function aovSAR.gen which takes the arguments: aovSar.gen(...
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1answer
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Can I calculate the integral of the O ring statistic from Ripley's K function?

I need to calculate the integral of the O ring statistic, and I do not see any available package to use in Rstudio that can provide me with this value. For example, here is the O ring statistic plot ...
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How to test whether or not a category (month) affects a continuous distribution (latitude, longitude)?

I am trying to answer a question as to whether or not the month of the year affects the geographical distribution of hurricanes in the Atlantic ocean. I know for example about hurricane season, and ...
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If Moran's I is non-significant can I treat my samples as being independent?

I have a set of data collected as part of a hydroacoustic survey-- essentially a boat drove back and forth over a harbour and took a snapshot of the fish biomass/density underneath the boat every 5 ...
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Paired t-test question for spatially distributed data

I have spatially distributed data at 50 locations for pre and post rainfall. So, 2 data points for each station. All the sites are different. Can I use paired t-test on this data?
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How to interpret large spatial effect in GAM?

This question has partly been asked before here: And does the deviance explained by the term indicate the extent of spatial autocorrelation? but didn't get an explicit answer. Although I'm not ...
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25 views

Modeling probability of action as a function of spatial distance

I'm trying to model how people interact with pins on a map, like the one below that shows pizza restaurants in the city of Chicago: I'm envisioning people interacting with this map in terms of "...
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How can I account for autocorrelation in location and seawater depth together in a gamm or lme model?

I'd like to use a genaral additive mixed model to test for a relationship between two variables that are autocorrelated accross space and depth. One clear case where this happens would be with highly ...
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Modeling at the census tract level with spatial considerations?

I want to evaluate how community level risk factors (from American Community Survey data) predict an outcome at the census tract level. All of my variables including my outcome are proportions, so ...
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47 views

Conley Standard Errors in Logit and Probit

I am looking for an implementation of Conley (1999, 2008) standard errors in logit and probit regressions. There is code targeting OLS regressions (1, 2, 3, 4), but I did not find anything adequate ...
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1answer
132 views

Is a chi square test appropriate?

I have a dataset which consists of fish density/biomass from two sampling periods (1 and 2) in two locations (A and B). In sampling period 1 locations A and B are both clear, while in sampling period ...
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How to generate two spatial data sets with different levels (low and high) of spatial autocorrelation?

Spatially correlated random fields can be generated (for example using geoR or gstat packages in R) by defining a model for the semi-variogram (e.g. exponential, gaussian, spherical, etc), as well as ...
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1answer
27 views

Making use of spatial context for a regression problem (possibly CNNs)?

I have as predictor variables geospatial raster data (~30 layers of various height models, modeled features, processed satellite imagery, ...) and as groundtruth/target variable a year per pixel (1867 ...
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Is linear regression appropriate here? Number of points within district based on racial proportion of that district

Each map district below is shaded blue according to the percentage of its white population. The colored points are healthcare facilities. I want to determine whether or not to reject the null ...
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Spatial Modeling: SAR vs CAR

I'm trying to understand why one would use a Conditional Autoregressive Model (CAR) vs a Spatial Autoregressive Model (SAR) to look at migratory decisions. I have been reading through some of the lit ...
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Mantel test alternatives: linear mixed models, with row and column ids of distance matrices as random effects?

Summary: I want to model in R the relationships between pairwise spatial distances, pairwise temporal distances, and pairwise Jaccard distances, with the goal of predicting the Jaccard distance ...
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two levels spatial regression in r

I need help to find the proper approach in R for an analysis of data. I have measures of a variable Y for various individuals, distributed in various geographical ...
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INLA Fitting logistic regression using bym or besag smoothing using neighboring spatial points instead of neighboring polygons

Ordinarily, if you want to account for the effect spatial boundaries have on certain variables. You could fit as follows as highlighted in Virgilio Gómez-Rubio's Bayesian inference with INLA article. <...
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Spatial Autoregression Model Implementation and Theory

I'm working through Hierarchical Modeling and Analysis for Spatial Data (Banerjee, Carlin, Gelfand), and I've started to have difficulty understanding how the theory connects with the R implementation....
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Modelling a multivariate spatial response to understand movement processes

I have position data for fish in a river relative to a point-source pollutant coming from upstream. When pollution levels are high, I expect the fish to either move downstream, deeper, or both. My ...
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1answer
36 views

Moran's I Statistic for skewed data

I'm trying to determine whether there is spatial autocorrelation in a set of data. I am using Moran's I statistic to test for spatial autocorrelation. The data was point data (instances of an event at ...
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1answer
27 views

Isotropic covariance functions on a lattice in $R^n$

In many spatial statistics references, isotropic covariance functions are usually defined in terms of Euclidean distance. But does this generalize to different norms on $R^n$? For example, if we took ...
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2answers
48 views

Comparison between two times series

I am looking at time series data, comparing the velocity with which different groups of animals move in a new environment. In its raw form, the data consists of trajectories from individual fish that ...
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1answer
50 views

Cell colony survival mapping in a particular spatial pattern

I am attempting to spatially map the cell survival in a given scanned image of a cell flask. Quick background: the cells have received a high dose of irradiation (protons/X-rays) delivered through a ...
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9 views

Spatial analysis with weights

I am estimating some spatial models. I would like to know if it is possible to include sample weights. In other words does it existna spatial counterpart to weighted least square? I tried to google ...
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35 views

Predict Longitude and Latitude time series

I have a dataset that describes location (latitude longitude) in different times of day. The dataset is for one day and has 10 minute intervals (so 144 observations). I need to predict the location at ...
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Terminology for smoothing methods: kernel density estimation, kernel smoothing, etc

I'm using what I have been referring to as 'kernel density estimation' to estimate the rates of a series of variables a, b, c from noisy observations distributed in ...
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8 views

How to upscale or downscale rasters of probability estimates

I need to compare two raster datasets that represent the predicted probability of fire over space. However, the spatial resolution of these datasets differs: one is composed of 1km pixels, the other ...
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Test to compare magnitude of spatial autoregressive parameter

I want to compare the impact of two different spatial matrices in a spatial autoregressive model. Consider the following spatial autoregressive model: $$y = \alpha + \rho_{1} W_{1} y + \beta X + \...

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