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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34 views

Downscaling climate data using DEM

I have gridded climate data (temperature and precipitation) at 0,1° resolution and I want to downscale it into a finer scale using digital elevation model. The relationship between the climate ...
2
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0answers
28 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. ...
0
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0answers
20 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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0answers
19 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 ...
1
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1answer
13 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 ...
2
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1answer
44 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 ...
3
votes
1answer
55 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 ...
1
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1answer
49 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
23 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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0answers
45 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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0answers
73 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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0answers
17 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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0answers
50 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 ...
2
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2answers
1k 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 ...
4
votes
1answer
260 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, ...
2
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2answers
121 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?
3
votes
1answer
170 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 ...
1
vote
1answer
808 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 ...
5
votes
1answer
308 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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0answers
128 views

Performing Moran Test using R? [closed]

I’m very new to R so please Bear with me: I have a set of data containing AREA Infested for each region ! and I want to know if there are any spatial autocorrelation between the regions! Here a sample ...
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0answers
389 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
74 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 ...
0
votes
1answer
288 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 ...
6
votes
1answer
801 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 ...
2
votes
2answers
240 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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0answers
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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0answers
144 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 ...
6
votes
1answer
280 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. ...
0
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0answers
73 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 ...
3
votes
0answers
31 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 ...
2
votes
0answers
90 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 ...
2
votes
0answers
427 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 ...
5
votes
2answers
3k views

How to implement Spatial Autocorrelation using QGIS or PostgreSQL (or any 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 ...
4
votes
2answers
301 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 ...
11
votes
2answers
1k 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 ...