[STATSGRASS] pseudo variograms

[rivera at pstat.ucsb.edu]

I have two questions about pseudo cross-variograms. It seems that they are only
calculated if the variables of interest are not co-located. Is there anyway to
calculate them even if the data is co-located? Cressie, 1991 pg 140 suggests
that using the 'classical' cross-variograms cannot guarantee optimal co-kriging
predictors. I would like to compare the results of each cross-variogram.
Secondly, if there is a way to calculate pseudo cross-variograms for co-located
data. Does the variogram function automatically standarize the variables? In
other  words, my three variables of interest DO NOT have the same measurement
units so each one of them should be standarized (by subtracting the mean and
dividing by the calculated standard deviation) for the empirical pseudo
cross-variogram equation to make any sense. Thanks ahead,
                                                                 Roberto