Tagged Questions

0
votes
0answers
29 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 ...
3
votes
0answers
104 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 ...
1
vote
0answers
29 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 ...
2
votes
0answers
63 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 ...
5
votes
1answer
363 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 ...
0
votes
0answers
82 views

Singular covariance matrix and Spatially-correlated random effects [closed]

I'm interested in incorporating spatially-correlated random effects into my model to explicitly account for between-observation spatial autocorrelation, such that spatial autocorrelation decreases ...
17
votes
3answers
689 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 ...
4
votes
0answers
71 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 ...
7
votes
1answer
168 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 ...
4
votes
1answer
254 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, ...
3
votes
0answers
217 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 ...
6
votes
2answers
479 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 ...
4
votes
4answers
386 views

Analyze and generate “clumpy” distributions?

Are there standard ways of analyzing and generating "clumpy" distributions? analyze: how clumpy is a given point cloud (in 1d, 2d, nd), what are its clumpy coefficients? generate or synthesize a ...
4
votes
1answer
213 views

Smoothness of a surface

I am currently working on a model which takes two parameters and produces a measurement statistic. Think of it as Z = f(X,Y). Z is a matrix of my statistics and I am creating a surface plot of it in ...