[R] nlme: spatial autocorrelation on a sphere

[David Winsemius]

On Sep 30, 2012, at 6:48 PM, Dan Bebber wrote:

> I have spatial data on a sphere (the Earth) for which I would like to run an gls model assuming that the errors are autcorrelated, i.e. including a corSpatial correlation in the model specification.
> 
> In this case the distance metric should be calculated on the sphere, therefore metric =  "euclidean" in (for example) corSpher would be incorrect.
> 
> I would be grateful for help on how to write a new distance metric for the corSpatial function.
> I believe there are several ways that distances on a sphere can be calculated in R, for example the "distMeeus" function in the geosphere library. However, I have no idea how to write this into a corSpatial function.
> 
> The aim is to end up with a metric  = "sphere" option that calculates great circle distances between points using latitude and longitude.

LMCTVTFY: http://cran.r-project.org/web/views/Spatial.html

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David Winsemius, MD
Alameda, CA, USA