# Tagged Questions

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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### What is the interpretation of eps parameter in DBSCAN clustering?

I want to cluster lat-long data such that all clusters formed will have radius<=1000 meters Questions What is the actual meaning of eps parameter? Please given an example. Will setting eps=1000 ...
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### 40,000 neuroscience papers on fMRI might be wrong

I saw this article in the Economist about a seemingly-devastating paper [1] casting doubt on "something like 40,000 published [fMRI] studies." The error, they say, is because of "erroneous statistical ...
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### How to get an azimuthal projection in an R plot? [migrated]

I want to use R for geospatial data analysis, and I want to use a map of my local area as from an azimuthal projection if possible. Is it possible to generate a map using R of an azimuthal projection ...
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### Test for difference of spatial/temporal distribution

I have the data of the average hourly consumption of electric power in 50 districst of a city, for the days of 2 months: ...
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### ML model selection for prediction of latitude and longitude

I am doing a project in which my aim is to predict the likely locations of a set of latitude/longitude points based on a couple of variables. Since I've never done any ML on locational data, which ...
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### Quantifying comparison of two different field data sets for the same 3D domain

I have a 3D domain (say a cube). The cube is discretized into an array of grid points. Each grid point holds a field data (like temperature, temperature gradient etc.). I would like to see if the ...
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### Why is my semivariance so high?

I am using variograms checking for spatial autocorrelation in a resiudal pattern produced by a GLMM-NB. In theory, the semivariance should be bounded between 0 and 1 (that´s what I think at least as I ...
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### Specifying the initial values of likfit function of geodata in R

I have a geostatistical data. For analysis, I am using geoR. I want to estimate the parameters. But likfit or ...
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### How to apply multiple random (clustered) factors in HGLM package? And how to solve Cholmod error: wrong dimensions? [closed]

I'm working on alien reptiles on Mediterranean Islands. The idea is to assess which variables are influencing/favouring reptiles introductions, which reptiles are being introduced and which island are ...
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### model two spatial auto correlation in spdep package in r

I hope to fit the spatial autoregressive model : $$y= \gamma_1 Wy + \gamma_2 By + X\beta +\epsilon. \quad (1)$$ where $W, B$ are different weight matrices. However, every references I've found only ...
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### Building a prediction raster when the statistical model was built from sampling units of different sizes

I would like to build a predictive map of capture success from a GAM. To build the GAM, I used data of capture success (dependent variable in the model) and proportions of land cover types (...
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### What does it mean that a variogram keeps increasing with distance?

I am modeling my 3D dataset with a Gaussian Process with square-exponential covariance. To test whether this is a good model, I subtract the mean from the observed data and then calculate the ...
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### How to define a study area for RIpley's L analysis?

I have a spatial point pattern which spans across multiple districts in the country. Now I want to examine its pattern using Ripley's L function. I know that Ripley's L function is used for ...
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### Spatial analysis of the network data

I'm a bit new in the spatial statistics (althought I'm not new in statistical analysis, particular in Bayesian inference). When we have point measurements in space - geostatistics/spatial statistics ...
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### Incorporating shifting spatial autocorrelation into a GLMM

So I'm examining a series of sites across a landscape for how wildlife use of these sites changes following treatment (reclamation). Treatment of these sites randomly took place over three years, and ...
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### Predictive model with geospatial data

I have datas of random events with gps and time variables. I would like to compute probabilities of an event happening at a given time and location. In the training set, we have about 1500 possibles ...
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### Correlation between spatial distributions

I have three bivariate data sets of different sizes and the same sampling interval. These represent the variation of dry river bed direction with distance at equidistant sample points. When plotted ...
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### When do I add elevation and time dimensions to my point process analysis [duplicate]

I have points I want to analyze their patterns. The points are of a real world data, let's say crime or settlements in the suburban or anything. I can apply elevation to it and I there is a time for ...
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### Difference between 2D and 3D point process

I have points that have elevation attached to them (they were 2D but then someone from the department of geography helped us applying elevation so now they are 3D). I'm about to explore options for ...
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### Does anyone have real world example for random point pattern

I have been writing a paper and need to give examples for the different patterns that are result of point process. It has to be real world examples. For clustered I give the example of settlements and ...
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### Can random point process generator generate pattern that is not random?

I am using esri arc to generate random points. I then analyze the pattern from this process using Average Nearest Neighbor which is also in esri gis but lets say it can be in any other software. Is ...
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### One side tests for example monte carlo

I looked at R for Spatial Statistics (spatstat) and I actually found out that it doesn't always have to be that below -1.96 is necessarily clustered and that above 1.96 must be uniformed. There is ...
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### Modelling impact of a variable varied across time but constant across space on dependent variables varied across space and time

I'm interested in exploring a simple problem of modelling an impact of variable varying across time on variables varying across space and time. Details Given are two data sets: Classical spatial ...
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### Lack of independence - how to analyze data from a time-series that are spatially correlated?

I am dealing with a species distribution. From aerial imagery, the species' presence has been assessed at specific locations by identifying the presence/absence of the species of interest under 9500 ...
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### Testing for spatial autocorrelation in residuals - time series

I have a ~25 year dataset of annual count of species abundance in several traps. Within a year, the abundance in a trap might be dependent on the abundance in another trap. I want to test the effect ...
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### Using Mantel test to check spatial independence in time series?

For my analysis in biology, I want to study the effects of several factors (climate, cultivated area...) on insect dynamics and phenology. For that, I have data of insect captures from several traps ...
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### Checking spatial autocorrelation by plotting residuals?

For my analysis in biology, I want to study the effects of several factors (climate, cultivated area...) on insect dynamics and phenology. For that, I have data of insect captures from several traps ...
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### If lat/long are features in a simple regression model, is the model going to account for the distance between data items?

That is closer items (geographically, according to lat/long) have correlated target variables. Example: prices of houses in a neighborhood are correlated. One way to handle this (continuing with ...
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### “Goodness for fit Chi” test on point pattern

Apologies, I have a few question today I hope there is no limit to how much I can ask here before you start billing me :) What is the meaning of Goodness for fit Chi-sqaure test? From the wikipedia ...
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### How to know if my data is homogeneous or not

This is for general understanding and I don't have a specific task or data I need to relate it to, but I'm trying to understand how do I know if my point data is homogeneous or inhomogeneous. Is that ...
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### What is the difference between IRP and CSR

In this presentation: sorry I couldn't upload the presentation so this is another example: https://www.e-education.psu.edu/geog586/l5_p13.html They are using CSR and IRP interchangeably. I think CSR ...
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### Are Pearson test and Chi-square test the same

I'm a bit confused with Chi-square and Pearson. I know Chi-square is: Chi-square = E (sum of) (Oi - Ei)-square / Ei What would the Pearson formula be if it is different? I don't think it is ...
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### Estimated values for Chi-square

To test if my point pattern is random, I am going to conduct a Chi square test. The data has 40 points divided to 3 by 3 tiles. Should I use Binomial or Poisson probability to calculate expected ...
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### What is the best test to check if pattern is uniformed?

Out of the following, which tests are best to use on uniformed data to make sure it is indeed dispersed $\chi^2$ Simple NNA High/Low clustering (Getis - ord) KNN (Ripley) Moran Monte Carlo
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### Do quadrats have to be equal in size?

I'm doing a quadrat analysis of point pattern. My study area is 2.3m by 2.3m. Can I have quadrats of 1sqm or does it have to be equal area? If quadrats are 1sqm, then four of them would be of full ...
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### What is the relationship between Intensity and Quadrats?

In point pattern analysis, what is the relationship between Intensity $\lambda$ and the quadrats analysis? Can $\lambda$ be calculated without or prior to dividing the area to quadrants?
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### Types of nearest neighbor analysis

I hear that there are different nearest neighbor analysis methods. Just nearest neighbor: $d = \epsilon (d)i / n$ But also higher order NNA, K and L NNA, refined NNA etc. Apologies as I don't have ...
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### Standard deviation in PPA

In Point Pattern Analysis I created a Standard deviation with a single degree (not sure what is the unit but $1\alpha$). Is there any use for counting the points within the area created? what does it ...
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### Effectiveness of mean centre and intensity

I am describing the Cells dataset (B.D. Ripley Modelling Spatial Patterns 1977) using numeric values of: intensity mean center Possibly standard deviation I cannot add maps but just present the ...
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### Who came up with the term “complete spatial randomness?”

I've seen the term "complete spatial randomness" widely used in literature but can't figure out who was the first to coin it. Who originated it, and is there a paper it can be cited to?
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### PPA- what are Regular, Random, Normal and Clustered?

In Point Pattern Analysis a particular dataset can be one of four, at least according to Wikipedia: Clustered, Normal, Random or Regular. The four: What is the name of those four options? Point ...
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### Is it OK to superimpose two different point patterns?

I am analyzing two datasets form Diggle's paper 1983: Cells Pine (actually Numata 1961) The cells are coordinates between 0 and 1 and the pine are coordinates between 0 and 5.7 (both are square ...
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### Area for nearest neighbor analysis

I'm using a software called ArcGIS to calculate the Nearest Neighbor Z value of the Cells dataset (Diggle 1983): The coordinates I have range as a percentage between 0 and 1. ArcGIS has a wizard ...
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### Does Null Hypothesis H0 in point pattern analysis have to be CSR?

I'm taking some tests on the Cells dataset (Diggle 1983). Tests include Chi / quadrant and Nearest Neighbor. By the looks of it, it's very not random. My H0 should therefore be that it is Dispersed....
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### Orientation of point dataset

Looking at the well-known Pine dataset (Numata, 1961) it appears in different articles in different orientations. 1983 Digggle: Then sometimes appears rotated: Or even flipped: Other than ...
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### What is λ in the context of Spatial Point Statistics?

What is a small lambda λ in the context of spatial point statistics and how do I calculate it for a given set of point? Specifically I am trying to calculate it for different sets of observations of ...
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### How to best represent a geographical area as point

I need to check a relationship(?) between land surface temperature (LST) and total population census tract (shapefile) wise where i am trying to relate social factors (e.g. total population, female ...
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### Multiple Regression: Spatial Covariate

Im trying to fit a multiple regression model that predicts deaths from earthquakes using magnitude and location of epicenter as predictors. I have no idea how to handle the spatial aspect ie the ...
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### How to interpret plots of point pattern models

I am struggling with the package spatstat and would really appreciate some help. I do not know how to interpret the "Fitted trend" and "Estimated SE" plots that one can get with the following code: ...
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### How can I run stats on 2D data?

For example, I have a collection of 2D points (x and y) on a 10x10 grid. What can I use to test if the points are from a uniform distribution (randomly distributed)? What can I use to see if they are ...