semat {spatial} | R Documentation |
Evaluate Kriging standard error of prediction over a grid.
semat(obj, xl, xu, yl, yu, n, se)
obj |
object returned by surf.gls
|
xl |
limits of the rectangle for grid |
xu |
|
yl |
|
yu |
|
n |
use n x n grid within the rectangle
|
se |
standard error at distance zero as a multiple of the supplied covariance. Otherwise estimated, and it assumed that a correlation function was supplied. |
list with components x, y and z suitable for contour
and image
.
Ripley, B. D. (1981) Spatial Statistics. Wiley.
Venables, W. N. and Ripley, B. D. (2002) Modern Applied Statistics with S. Fourth edition. Springer.
data(topo, package="MASS") topo.kr <- surf.gls(2, expcov, topo, d=0.7) prsurf <- prmat(topo.kr, 0, 6.5, 0, 6.5, 50) contour(prsurf, levels=seq(700, 925, 25)) sesurf <- semat(topo.kr, 0, 6.5, 0, 6.5, 30) contour(sesurf, levels=c(22,25))