plugincvc {lacunaritycovariance} | R Documentation |
Plug-in moment covariance estimator
Description
This function computes the plug-in moment covariance estimate of a stationary RACS from a binary map.
For a stationary RACS, , the covariance
for a vector
is the probability of two points separated by a vector
are covered by
Usage
plugincvc(xi, obswin = NULL, setcov_boundarythresh = NULL)
Arguments
xi |
An observation of a RACS of interest as a full binary map (as an |
obswin |
If |
setcov_boundarythresh |
To avoid instabilities caused by dividing by very small quantities, if the set covariance of the observation window
is smaller than |
Details
The plug-in moment covariance estimator is (Serra, 1982)
where is the set covariance of the observation window
and
is the set covariance of the foreground within
.
plugincvc
uses Fourier transforms to calculate the set covariance (using the setcov
of the foreground and observation window.
Vectors with small are eliminated using
setcov_boundarythresh
as division by small values is numerically unstable.
Value
A SpatStat im
object containing the estimated covariance.
Author(s)
Kassel Liam Hingee
References
Serra, J.P. (1982) Image Analysis and Mathematical Morphology. London; New York: Academic Press.
Examples
xi <- as.im(heather$coarse, na.replace = 0)
covar <- plugincvc(xi)