[R-sig-Geo] semivariogram + coordinate units

[Pedro Mardones]

Dear list members;
I'm a newbie in geostatistics so this question may have an obvious
answer that I'm not aware of (sorry about this). I've a grid of points
in which the x-axis is measured in cm (from 1 to 20) and the y-axis in
meters (from 1 to 20). So basically I have 20 x 20 points to work
with. Here is where I'm kind of confused. Do I need to transform the
coordinates to the same units, say cm or meters, before obtaining an
empirical semivariogram? What could be the effect of using the
coordinates in the given units (ie without transforming them to the
same units) on the analysis?
Thanks for any hint
PM