California Soil Resource Lab

Before computing transformation matrix

Submitted by dylan on Fri, 2008-02-01 05:26.

... it might be good to compute a trend surface of the square differences between the two sets of coordinates, at the sites of the good coordinates.

## continued from above example:

## compute square difference:

c$sqdiff <- with(c, sqrt((nx-x)^2 + (ny-y)^2))

##

library(gstat)

##

coordinates(c) <- c('nx', 'ny')

coordinates(d) <- c('x', 'y')

gridded(d) <- TRUE\

x <- gstat(sqdiff ~ 1, data=c, degree=2)

x.trend <- predict(x, newdata=d)

spplot(x.trend, "var1.pred")

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