Calculates Cohen's kappa and variance estimates, within a 95 percent confidence interval.
Usage
ecospat.cohen.kappa(xtab)
Arguments
xtab
A symmetric agreement table.
Value
A list with elements 'kap', 'vark', 'totn' and 'ci' is returned.
'kap' is the cohen's kappa, 'vark' is the variance estimate within a 95 percent confidence interval, 'totn' is the number of plots and 'ci' is the confidence interval.
Details
The argument xtab is a contingency table.
xtab <- table(Pred >= th, Sp.occ)
References
Bishop, Y.M.M., S.E. Fienberg and P.W. Holland. 1975. Discrete multivariate analysis: Theory and Practice. Cambridge, MA: MIT Press. pp. 395-397.
Pearce, J. and S. Ferrier. 2000. Evaluating the predictive performance of habitat models developed using logistic regression. Ecol. Model., 133, 225-245.