[R-sig-Geo] Kriging with External Drift, multivariate experience?
edzer.pebesma at uni-muenster.de
Mon Nov 9 11:42:00 CET 2009
Tobin Cara wrote:
> Thank you all for your previous help. I began using R 2 weeks ago, and I am getting somewhere finally. I have been able to run universal kriging with a Digital Elevation Model trend. Now, does anyone have experience with kriging more than one trend variable?
> I assume you have to have the other variables defined at the same locations as the original grid and then at the new grid. However, can more than one new grid be defined?
> For example,
> elev_ked <- krige(meanPrec~Z+LAM, meanPrec, newdata=elev, fitted_vario)
> In this example, I want to krig the mean Precipitation relative to the elevation Z and a Limited Area Model (LAM). There is only one way to define the newdata that I know and in this case I am interpolating back to the Digital Elevation Model 'elev'. If I want to interpolate back to the LAM grid, I presume I change to newdata=LAM?
> However, is there an approach that uses the entire newdata grid of elev and a LAM grid for interpolation?
yes; make them into a single object, e.g. by
elev$LAM = LAM[]
which only make sense if elev and LAM have the same topology (grid
> Do they have to be at the same resolution?
> Thank you so much!
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