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Questions tagged [autocorrelation]

A quantitative measure of the linear relationship among values in a dataset and the values (from the same dataset) at nearby locations.

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Measure for spatial autocorrelation in fire occurrence data

I am trying to determine the variables that predict forest fire occurrence in a region in Chile. Firstly, I determined burned areas using LANDSAT data and the dNBR-index. I ultimately made a raster ...
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35 views

Randomly Sample Raster Pixels With a Minimum Distance in QGIS

Is there a way I can sample random raster pixels from a satellite image with QGIS or QGIS plugin? I also need each randomly-chosen pixel to have a pre-defined minimum distance from the other raster ...
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60 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
152 views

Compute Moran's I on more than one attribute

I am trying to compute global Moran's I to check for spatial autocorrelation among areas of a city. I am using python, in particular geopandas and pysal. My geodataframe looks like: District_name|...
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1answer
55 views

Geographically Weighted Regression with overlapping polygons

Is it statistically correct (or possible at all) to calculate a spatial regression with (partly) overlapping spatial areas? I have market areas as the spatial unit with different sociodemographic, ...
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1answer
76 views

Generate spatial weight matrix from file in ArcGIS

I am trying to create a spatial weight matrix from an existing file in ArcGIS. I need to use another file, as opposed to generate the weights in Arc, because I define non-standard weights. The ...
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1answer
141 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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30 views

Accounting for spatial autocorrelation in glm

I have checked my model(a logistic regression) and found it has spatial autocorrelation. Thus, to account for this correlatedness or non-independence I created this covariate auto_weight using spedep ...
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252 views

How to check spatial autocorrelation correctly in a glm

I ran a binomial glm as below and from plotting observations i know that there are many observations close to each other and i expect them to be highly correlated. For this matter after selecting the ...
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110 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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1answer
69 views

Point Similarity Clustering

I am new to geographical statistics so please pardon this question if it is a duplicate. I would like to test if points that are similar are more or less likely to be near each other. I am latitude ...
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1answer
41 views

Are points similar to nearby points using R?

I am new to spatial statistics. I am trying to determine if points close together are more or less similar. Specifically, I have a series of lat/long points for alligators nests. At some nests, one ...
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197 views

Using Moran's I test for spatial autocorrelation on residuals from logistic mixed model?

I know that tests using Moran's I are not appropriate for binary outcome variables, but can I use that test on the residuals from a logistic mixed model to see if spatial dependence is unaccounted for?...
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729 views

Moran's I on 2D arrays/rasters?

I would like to apply Moran's I spatial auto-correlation measure to 2D arrays or raster files in Python and I am wondering if there is an available implementation for it. I know Pysal offers an ...
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34 views

Correcting for correlation of kernel density of events to that of their distance from separate feature using ArcGIS Desktop?

I have a kernel density raster of recorded events. These events are correlated to their distance from a linear feature. In other words, density is higher near this line because it is a 'starting point'...
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1answer
749 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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2answers
209 views

Testing species distribution model residuals for spatial autocorrelation?

I build a species distribution model with data from location A and tested it on location B. The picture shows a rastermap of location B and what I guess should be the model residuals. Green - are ...
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1answer
516 views

Accounting for spatial autocorrelation in rasters

Background: I have a set of fine resolution rasters for the Florida peninsula. These rasters are going to be used in species distribution modeling. Many of these rasters represent variables that are ...
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1answer
708 views

Test Statistic, p-value interpretation for Local Moran's I [closed]

I am using Local Moran's I in the spdep in R. See this question: https://stackoverflow.com/questions/44104008/spatial-autocorrelation-between-time-series-in-r?noredirect=1#comment75251231_44104008 ...
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1answer
201 views

Autoregressive parameter from autocorrelation using R

I was wondering how to get autoregressive (AR) parameter ("rho") from an autocorrelation plot using R. Below I generated a correlated data and then provided a simple approach to produce an ...
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137 views

for loop in ArcMap: calculating Moran's I for 300 cities

I would like to calculate Moran's I for neighborhoods (tracts) in each of the 300 studied cities. I can calculate Moran's I for each city through Spatial Statistics Tools->Analyzing Spatial Patterns->...
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1answer
564 views

Why Spatial autocorrelation (Global Moran's I) is producing a p value of 0?

I am undertaking spatial autocorrelation (Global Moran's I) in ArcMap 10.3. The p value returned is 0, does this just mean its extremely significant or is this an incorrect result?
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Using spatial regression on interpolated surfaces? [closed]

I have two raster surfaces where I want to test to see If any relationship (A depending on B) can be found and if so if that relationship is statisticaly significant. What are key issues to consider ...
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341 views

Removing spatial autocorrelation (SAC) using Moran's Eigenvectors and predict distribution?

I successfully managed to incorporate moran's eigenvectors as predictor to my species distribution model using GLM (logit). I followed Dormann et al. (2007) and the appendix. I think I got corrected ...
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127 views

How to properly address autocorrelation for logistic regression of spatial data

Background for the Model: https://stats.stackexchange.com/questions/268201/how-to-increase-mcfadden-score-and-choose-proper-predictor-for-binary-logistic-r Data I have: Forest loss points Forest ...
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Is aggregating points to areal units ever useful - Spatial statistics

I have a large point dataset of a population (By population, I mean that it was not a sample e.g. all houses in a county with an attribute such as size, price, age, etc.). Each point represents each ...
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677 views

Calculating spatial autocorrelation of raster values?

R is perfectly willing to compute a Moran's I statistic (and probably all of the other autocorrelation metrics) for a raster. As best I can tell, PySal and ArcMap's autocorrelation tools specifically ...
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Spatial Autocorrelation with a low number input feature

I am an archaeologist using ArcGIS to run spatial statistics/analyses on my data. I want to study the spatial autocorrelation of artifact categories found within house structures across an ...
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1answer
1k views

Spatial outliers detection in R?

What is the best way to detect spatial outliers in R? With spatial outlier detection I mean: Discover the objects whose non-spatial attribute values are significantly different from the values of ...
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1answer
159 views

Inputs for spatial autocorrelation

I am trying to use the spatial autocorrelation function in the statistical analysis toolbox but I am unsure what I need to set as the inputs. I want to use it to test for autocorrelation in a set of '...
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2answers
188 views

Error Message when Running Global Morans with Spatial Weights Matrix

I am attempting to run a global Moran's I test with a spatial weights matrix, however when I run the process I always receive an error message and I was hoping someone could point out when I am going ...
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0answers
56 views

OLS tool in ArcMap 10.4: Spatially Autocorrelated Explanatory Variable

I am performing ordinary least squares regression analysis on two variables: K concentration in soil as explanatory variable, and thickness of stalk of plants as the dependent. The K-concentration ...
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628 views

R-Studio0.99, How to compute correlation between two rasters and serial correlation

I am using R.Studio0.99 version installed on my HP Laptop 4th generation (8GB RAM) windows 8 operating system and I know how to use R studio and some of the library to incorporate spatial data (raster,...
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1answer
384 views

Spatial correlograms for binary raster?

I have binary raster data (deforestation hotspot or not) that I would like to plot spatial correlograms for in R, to look at spatial autocorrelation over different spatial lags. I came across this ...
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1answer
162 views

How to work with Spatial Autocorrelation (Morans I) on equal weighted point

I have a point feature class. All points are the same, it's not weighted. I want to use Spatial Autocorrelation (Morans I) tool but it only takes a field for weight. I tried fooling it by adding a ...
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1answer
491 views

What is the difference between spatial regimes and spatial heterogeneity?

Let me cite excerpts from the GeoDA-Gloassary (https://geodacenter.asu.edu/node/390) Spatial regimes: Spatial regimes are a form of spatial heterogeneity, which implies structural differences ...
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141 views

Interpreting variogram: negative values beyond model sill?

The negative values mean that there is negative autocorrelation at some far distance, like a repulsion. How would this affect assessment of the range? (This is just for learning the scale of a ...
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42 views

Why are spatial lagged exogeneous variables rarely used?

In the publication "Regional Productivity and Income Convergence in the Unified Germany 1992-2000" (link) it is claimed without detailed explanation: "Usually, in spatial econometric models only ...
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65 views

Choosing the range of the correlogram with an irregularly shaped area

I am doing correlograms (Moran's I) between 125 plots. Those plots are located in large patches in my study area (see figure). The entire study area is approximately 2000 x 2000 m. I know that the ...
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56 views

Comparing different degrees of local spatial association

I have two data sets and want to compare/evaluate their degree of spatial association expressed in terms of the LISA statistic. The local Moran's I statistic gives for each point a (pseudo) p-Value ...
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1answer
479 views

Algorithm for spatial clustering?

I have a series of 2D maps with values ranging 0.0 to 1.0 spread all over. The algorithm that produces them is an application of the fractional Brownian motion. Each map measures 101x101 pixels or ...
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0answers
230 views

How to calculate Spatial Autocorrelation of grouped points in ArcMap 10.2.2

I have 32 points uniformly distributed with 7 attributes that comprises continuous values. I used the Grouping Analysis tool in ArcMap 10.2.2. I set 2 groups that have clear differences and are also ...
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1answer
898 views

Interpreting semivariogram with high nugget effect?

I made a semivariogram in R using package gstat, variogram() function. I want to see if there is spatial autocorrelation in the residuals of my model (species abundance as a function of habitat, ...
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361 views

Interpreting Global Moran's I and should I krig?

I am trying to weigh up if kriging (or cokriging) the residual error from my model is a valid approach. My first step was to compute whether the error is spatially autocorrelated. I have done this ...
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1answer
67 views

Conflicting results for spatial autocorrelation tests

I am working with an imbalanced (5%/95%) presence/absence dataset. I've created 25x25 m. raster cells that are categorized '1' or '0'. My Geary's C result (~0.993) and Moran's I result (~0.0045) are ...
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1answer
114 views

A way to measure whether two variables have similar spatial distributions?

I'm doing a project that's looking at a certain disease outbreak and vaccination in California counties using arcmap. I have aggregated data joins for disease outbreak rate, personal belief exemptions,...
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1answer
303 views

Spatial autocorrelation analysis (Global Moran`s I) suspicious z-score

I have a doubt concerning the Spatial autocorrelation analysis Global Moran's I, in ArcGIS 10.2. I did the analysis with 3.372 features of a defined study area, and it showed that the features are ...
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1answer
219 views

Spatial correlation

I want to do spatial correlation with many variables. In fact when I do correlation densities points results are better than when I work with attributive data. Can I use the result of the density of ...
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44 views

Calculating Autocorrelation in Different Zones

I'm an intermediate-ish user of ArcGIS 10.2 (win7 pro, hardware robust enough to handle very large datasets and computationally intensive analysis) with perhaps a simple problem that's evading me ...
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140 views

Using Ripley's K Function in ArcGIS for coral density along a transect?

I have some data from transects taken in a mangrove system. I want to analyze the spatial distribution /some sort of spatial statistics of how clumped/dispersed corals are along this linear transect. ...