ossfim: Kriging standard errors as function of grid spacing and block size

Description

Calculate, for a given variogram model, ordinary block kriging standard errors as a function of sampling spaces and block sizes

Usage

ossfim(spacings = 1:5, block.sizes = 1:5, model, nmax = 25, debug = 0)

Arguments

spacings

range of grid (data) spacings to be used

block.sizes

range of block sizes to be used

model

variogram model, output of vgm

nmax

set the kriging neighbourhood size

debug

debug level; set to 32 to see a lot of output

Value

data frame with columns spacing (the grid spacing), block.size (the block size), and kriging.se (block kriging standard error)

References

Burrough, P.A., R.A. McDonnell (1999) Principles of Geographical Information Systems. Oxford University Press (e.g., figure 10.11 on page 261)

Burgess, T.M., R. Webster, A.B. McBratney (1981) Optimal interpolation and isarithmic mapping of soil properties. IV Sampling strategy. The journal of soil science 32(4), 643-660.

McBratney, A.B., R. Webster (1981) The design of optimal sampling schemes for local estimation and mapping of regionalized variables: 2 program and examples. Computers and Geosciences 7: 335-365.

read more on a simplified, web-based version on http://www.gstat.org/ossfim.html

Examples

Run this code

x <- ossfim(1:15,1:15, model = vgm(1,"Exp",15))
library(lattice)
levelplot(kriging.se~spacing+block.size, x, 
  main = "Ossfim results, variogram 1 Exp(15)")
# if you wonder about the decrease in the upper left corner of the graph,
# try the above with nmax set to 100, or perhaps 200.