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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26 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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11 views

Bivariate Moran's I and LISA statistics using two diverse variables at different time

I'd like to use the bivariate Moran's I and LISA statistics using two diverse variables at different time. For example, Population in 1990 and firms' localisation in 2000. Please, I would like to ...
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1answer
20 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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36 views

Trouble shooting Incremental Spatial Autocorrelation/Hot Spot Analysis

I'm trying to do a spatial analysis of rural school closings in Brazil (ultimate objective to do OLS/GWR). I have census data from 2005 and 2014, from which I've calculated the relative percentage of ...
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21 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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19 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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21 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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22 views

What are the practical differences between Moran's I and Geary's C

What are the practical differences between Moran's I and Geary's C for gridded datasets (e.g. temperature) on a continental scale such as USA? Which is more applicable?
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9 views

How to choose the correct range for Moran's I correlogram with irregularly shaped areas? [duplicate]

This question was first ask on Cross Validated, but I think it might be better suited to Geographic Information Systems. First question here, so I apologize if it doesn't fit! I am doing correlograms ...
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19 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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32 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
89 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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71 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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115 views

Interpreting semivariogram high nugget

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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78 views

Variogram to assess spatial auto-correlation in grouped surveys in R

I have a large dataset with coordinates of survey locations, and results for presence or absence of a species. These surveys are spatially clustered, with four in a line separated by 1km each, and the ...
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100 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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82 views

How to create an autocovariate in ArcGIS for use in autologistic regression model

I am trying to create an autocovariate variable for use in an autologistic regression. I have a GIS point Shapefile of the response variable, in binary form for presence/absence of a plant species. ...
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97 views

Moran's I correlogram: advices on interpretation

I was interested in assessing to what extent the occurrence of a given land characteristics is influenced by autocorrelation. I have a point shape file, and for each point the presence/absence of that ...
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74 views

spatial autocorrelation and calculation of autocovariate term

I was reading some literature on spatial modeling, where it is stressed that in using regression (e.g., the Generalized Linear Model family, comprising Logistic Regression for example) the possible ...
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1answer
29 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
66 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 ...
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1answer
116 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
97 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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0answers
31 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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58 views

ArcGIS implementation of an R-script for estimating spatial autocorrelation

How do I implement the following in ArcGIS? rho.from.data <- function(ras){ require(spdep) require(maptools) #-- Generate Spatial Pixels data frame from raster file --# r2r <- as(ras, ...
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91 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. ...
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22 views

Getting incorrect results for Geary's Coefficient algorithm (incorrect math?)

I'm not sure if anyone here can help me with this, but I'm currently working on a program that uses a spatial autocorrelation algorithm to analyze patterns in an image. It's supposed to return values ...
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71 views

Unexpected Moran's I value in R using a chessboard example

I'm running into unexpected values for Moran's I when using the Moran.I function in the R library "ape". My understanding is that a chessboard is an example of perfect negative spatial ...
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2answers
2k views

Variogram model fit compatability among geoR, gstat, and nlme packages in R

I'm trying to specify the covariance structure parameters in a linear mixed model (using the correlation structure facilities in nlme). The parameters are estimated from a gstat or geoR variogram ...
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1answer
536 views

Classical or robust variogram for incorporation into generalized linear model

I'm modeling counts of organisms over time at eleven locations. I'd like to account for temporal autocorrelation in the counts, assuming it's present. As the data are not equally spaced in time, ...
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2answers
199 views

Geary's index of spatial autocorrelation

Does anyone knows If there is a way to calculate Geary's index of spatial autocorrelation on open source gis?
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1answer
202 views

Can I ignore very low levels of spatial autocorrelation in my data?

I have >1 million postcodes clustered in ~7000 middle super output areas for England and Wales which I'm analysing using MLwiN. I have used a multilevel model with random effects and have clustered ...
3
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1answer
3k views

Interpreting Moran's I results

I have a sample of data taken from regions of a country! i want to test if there are any spatial autocorrelation on my data using Moran Indice test. the null hypothesis: is that there is no spatial ...
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1answer
454 views

Specifying Bayesian Spatially lagged dependent (SAR) variable regression in winBUGS or Stan

I have been looking for code example on how to specify a SAR spatially lagged dependent variable regression in winBUGS (geoBUGS) or, if possible, in Stan. I mean, something of the format: Y = beta_0 ...
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625 views

Lagrange Multiplier in lm.LMtests (spdep package for R)

Are the Lagrange values comparable in lm.LMtests? If both RLMerr and RLMlag are significant, would the test with the largest Lagrange value be considered 'better' at explaining the spatial ...
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0answers
114 views

Getis-Ord GI and Moran's I when interested in clustering of data values not points

I have a dataset with many clustered (often coincident) points, each of which contains data. I am not interested in the fact that the points are obviously clustered. I would like to know whether the ...
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1answer
401 views

How do I generate a correlogram from a GeoTiff using R?

I'm trying to evaluate the scale of spatial autocorrelation for a bunch of rasters I have as GeoTIFFs. I'd like to be able to do this entirely using R, in order to maintain smooth workflow. What's ...
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1answer
1k views

R raster Package Moran's I interpretation

I am using raster package to calculate the local Moran's I . The example gives the range of Moran's I between - 1 to 2.47. On my own data I have see the value range -3.070423 - 7.228558 How can ...
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2answers
369 views

R - What is the purpose of .GAL lattice file?

Could someone please explain to me what the purpose of a .GAL lattice file is? I want to see if my data are spatially autocorrelated and I've been following Bivand (2013). I have loaded my polygon ...
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24 views

How do I randomly alter a raster with som correlation

I need to randomly alter an existing raster. The original raster is essentially a topography map that measures its values around a normal distribution ranging between 0.5 and 1.5 The new raster ...
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189 views

Contradictories results with Moran's I and Geary's C

I have contradictories results for both index. One side Moran's I says there is a positive correlation , but Geary's C says there isn't any correlation. Geary's C is more sensitive local ...
7
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1answer
572 views

Help interpreting Moran's I and Geary's C results

I've got some doubts about how to interpret some results for a work. And I) would like someone could confirm or improve my conclussions. I made a correlation analysis with SEXTANTE software in gvSIG. ...
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81 views

Autocorrelation: Best way to assess mixed uses and building scales?

I am trying to find the best way to measure the spatial distribution and scale of "mixed-uses". i.e. the mix of different building use categories such as residential, commercial, industrial, etc. I am ...
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32 views

Finding closest anticorrelated polygon or automate what is learned in semivariogram?

I am trying to do spatial autocorrelation of sorts based on a layer of polygons of mean rainfall data. I want to see how rainfall deviates from a certain point on the landscape. Essentially, I want to ...
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0answers
104 views

Determining spatial cluster of park types in ArcGIS

Question 1: I am trying to determine which (if any) of my different park types are spatially clustered across my study area (city boundary). There are 162 total parks, 9 nominal categories (which ...
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0answers
517 views

Problems with spatial autocorrelation in Geographically Weighted Regression (GWR) analysis

I have conducted an Ordinary Least Squares (OLS) and Geographically Weighted Regression (GWR) analysis in ArcGIS where I have tried to predict biodiversity patterns in an area. When I examine the ...
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2answers
5k views

Implementing Spatial Autocorrelation using QGIS or PostgreSQL or any other free application?

I am a total newbie on the GIS scene so I hope this is not a stupid question. I have two layers in a PostgreSQL database. The first layer contains points where events happened in Europe. The second ...
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2answers
360 views

Autocorrelated DEM with QGIS or Grass

I was wondering if there is a way to make an Autocorrelated DEM within QGIS or Grass. I am looking to do this with stereo aerial photography. I am able to do this with a number of COTS tools, but I ...
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2answers
2k views

Regression Model and Spatial Autocorrelation

I have used OLS and GWR for validating the dependencies between two distinct database. The Residual Square for GWR is 0.82 and thereby making it the right regression model to be used for determining ...