Computes the cross covariance matrix between two sets of locations for a spatial random process with a given covariance structure. Typically the two sets are a learning set and a test set.
covMat1Mat2(object, X1, X2, nugget.flag=FALSE)an object specifying the covariance structure.
a matrix whose rows represent the locations of a first set (for instance a set of learning points).
a matrix whose rows represent the locations of a second set (for instance a set of test points).
an optional boolean. If TRUE, the covariance between 2 equal locations takes into account the nugget effect (if any). Locations are considered equal if their euclidian distance is inferior to 1e-15. Default is FALSE.
a matrix of size (nb of rows of X1 * nb of rows of X2) whose element (i1,i2) is equal to the covariance between the locations specified by row i1 of X1 and row i2 of X2.