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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1k 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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73 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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727 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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373 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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0answers
40 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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364 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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0answers
70 views

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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38 views

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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153 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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62 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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309 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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116 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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204 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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130 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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58 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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0answers
649 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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146 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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232 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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45 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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141 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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33 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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225 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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312 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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443 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 variations, ...
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22 views

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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43 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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36 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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37 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'...