Fast calculation of block-block covariance
Christoph, package spatialCovariance (on CRAN) seems to do this, by reading it's description. Please share with us whether it did what you wanted or not; I acknowledge that this is a problem that other packages could benefit from a fast solution to this problem. Bests, -- Edzer
Christoph Hofer wrote:
Dear all I'm a Ph.D. student in Environmental Sciences at the ETH Zurich and new to this list, but I have searched for an answer to my problem in the list archives and couldn't find anything. I have the following problem: I want to calculate the block-block covariance C(B1,B2) among two blocks of arbitrary shaped polygons (non-rectangular). In the gstat package the block-block covariance is calculated by discretizing the blocks by points (via the command "nblockdiscr" one can choose the number of points in the polygon). I wrote R code with the function integrate, but to calculate the block-block covariance a quad integral of the covariance function has to be calculated and therefore even for polygons with a few vertices my code is very slow. Is there a fast solution (algorithm, package or function in R, aside from the gstat solution) to calculate the block-block covariance of arbitrary shaped polygons? Best regards Christoph Hofer
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