correlogram {spatial} | R Documentation |
Compute spatial correlograms of spatial data or residuals.
correlogram(krig, nint, plotit = TRUE, ...)
krig |
trend-surface or kriging object with columns x , y , and z
|
nint |
number of bins used |
plotit |
logical for plotting |
... |
parameters for the plot |
Divides range of data into nint
bins, and computes the covariance for
pairs with separation in each bin, then divides by the variance.
Returns results for bins with 6 or more pairs.
x
and y
coordinates of the correlogram, and cnt
, the number of pairs
averaged per bin.
Plots the correlogram if plotit = TRUE
.
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.ls(2, topo) correlogram(topo.kr, 25) d <- seq(0, 7, 0.1) lines(d, expcov(d, 0.7))