Compute cross-type nearest neighbor distances
crossNN(dist, n1, n2, w = rep(1, n1 + n2))a distance matrix, the upper n1 x n1 part contains distances between objects of type 1 the lower n2 x n2 part contains distances between objects of type 2
numbers of objects of type 1
numbers of objects of type 2
optional weights of the objects (length n1+n2), defaults to equal weights
a (n1+n2) x 2 matrix with the cross-type nearest neighbor distances and weights given as the sum of the weights of the involved objects