Calculate the covariance matrix for the difference between two K-functions under random labelling of the corresponding two sets of points.
khvmat(pts1, pts2, poly, s)
A matrix containing the covariances, with the variances on the diagonal.
An object containing the case locations.
An object containing the control locations.
Polygon enclosing the points in pts1 and pts2.
A vector of distances at which the calculation is to be made.
Diggle P.J and Chetwynd A.C (1991) Second order analysis of spatial clustering Biometrics 47 1155-63; Rowlingson, B. and Diggle, P. 1993 Splancs: spatial point pattern analysis code in S-Plus. Computers and Geosciences, 19, 627-655; the original sources can be accessed at: https://www.maths.lancs.ac.uk/~rowlings/Splancs/. See also Bivand, R. and Gebhardt, A. 2000 Implementing functions for spatial statistical analysis using the R language. Journal of Geographical Systems, 2, 307-317.
secal