# Tagged Questions

37 views

### Comparings BIC of lme models with and without a correlation function

I have created an lme model using the same predictors both with and without a specified correlation structure based upon distance between the points (lat/long). I ...
89 views

### How to generate normal random variable vector which is spatially auto-correlated

I would like to generate normal random variable vector $\boldsymbol{x}_1$, which is correlated with $\boldsymbol{x}_2$. Also, I would like to introduce some kind of spatial auto-correlation into ...
21 views

### Convergence problems created by jittered coordinates

I am creating a mixed model and including a spatial correlation. My data points include lat long values although some are duplicated. I have two questions about dealing with these. To specify the ...
36 views

### Spatial autocorrelation (SAC) while analysing survey data

I am confused about some aspects of spatial autocorrelation usind survey data (survey which is repeated every year). I have data from 1991 to 2012 with sampling region pretty consistent every year. I ...
207 views

### Spatial autocorrelation — GLM, autocovariate, MEM (Moran's eigenvector mapping)

I am currently working on two marine species distribution modelling and also on their overlap distribution. For this I use a binomial logistic regression model (GLM) with response being, respectively, ...
113 views

### Estimating model error in $k$-nearest neighbours with strongly spatially autocorrelated training data

In the palaeoclimate world, palaeoecologists have used spatial training sets of say sea-surface temperture (SST) and related this to micro-organisms living at the locations where SST was measured. A ...
104 views

### Why is Moran's I not equal to “-1” in perfectly dispersed point pattern

Is wikipedia wrong...or I don't understand it? Wikipedia: The white and black squares ("chess pattern") are perfectly dispersed so Moran's I would be −1. If the white squares were stacked to one ...
76 views

### need derivation of join-count variance (spatial autocorrelation stat), know where it is?

I am using interlibrary loan to get Cliff and Ord's book Spatial Processes, but the semester just ended and it is slow now. On page 18ish of this book, Cliff and Ord show how the variance for the ...
227 views

### What does the Semivariance tell me?

I am looking at a Semivariogram. I know it shows me the relationship between distance and semi-variance. I also know that at the end of the range the distance no longer auto correlates. What I am ...
69 views

### regression: handling negative autocorrelation in R?

I am running a regression in the R package nlme (but am not constrained to only that package). I am changing the spatial scale of the analysis over a few regression runs as a form of sensitivity ...
163 views

### Spatial autocorrelation of non-homogeneous point data in irregularly shaped sample plots

Let's assume we registered the position of all individuals of different plant species within 3 irregularly shaped sample plots that are very close the each other. As an example, I put 2 pictures with ...
33 views

### Possible outcomes of approximate profile-likelihood estimator (APLE) for spatial autocorrelation

I've been working with spatial autocorrelation for a while and now I'm trying to move from more traditional estimators such as Moran's I or Geary's C to the new APLE estimator. I read Li's papers on ...
78 views

### Calculating R-squared values from a semivariogram

I have some spatially autocorrelated vegetation data, and would like to know the how well tree size measured at one location can predict tree size in plots 100m away. I've made a semivariogram of ...
75 views

### Is there any free software for Oden's Ipop?

I'm trying to use software that has an Oden's Ipop Statistics function for testing spatial autocorrelation adjusted for population. I prefer knowing if something is available for FREE. I have ...
532 views

### Linear Regression and Spatial-Autocorrelation

I want to predict Tree Heights in a certain area using some variable obtained through remote sensing. Like approximate Biomass, etc. I want to first use a linear regression (I know it's not the best ...
1k views

### Why does including latitude and longitude in a GAM account for spatial autocorrelation?

I have produced generalized additive models for deforestation. To account for spatial-autocorrelation, I have included latitude and longitude as a smoothed, interaction term (i.e. s(x,y)). I've based ...
78 views

### Can you use a spline function of the spatial coordinates to control for spatial autocorrelation? [duplicate]

Possible Duplicate: Why does including latitude and longitude in a GAM account for spatial autocorrelation? I am interested in the effect of a predictor vector $X_i$ on a binary outcome ...
231 views

### Modeling a spatial trend by regression with the $(x,y)$ coordinates as predictors

I plan to include coordinates as covariates in the regression equation in order to adjust for the spatial trend that exists in the data. After that, I want to test residuals on spatial autocorrelation ...
366 views

### In spatial regression, what is a spherical autocorrelation structure?

I have a large gridded dataset for the globe (i.e a spherical, wraparound surface) that I'm applying spatial regression to (using a CAR model). I've been using the default autocorrelation function, ...
282 views

### How to estimate measurement error on spatially autocorrelated gridded data when aggregating grid cells

I would like to estimate the measurement error when aggregating (via arithmetic mean) gridded spatial data. The goal is to come up with the mean elevation (or some other spatially continuous ...
546 views

### Choice of weight function in Moran's I

I'm doing an autocorrelation analysis for a spatially distributed collection of observations. To perform my analysis, I am using Moran's I statistic. My questions are: (1) What are the implications ...