[R-sig-Geo] How to make directional h-scatterplots

[Waichler, Scott R]

What is the best way to make directional h-scatterplots (lagged scatterplots)?  There is hscat() in gstat, but I don't see a way to limit point pair selection to certain directions.  I have a 3D dataset based on logs from 30 different wells, with vertical spacing between points and total extent both smaller than horizontal spacing and extent. 

Here is what I have figured out so far.  For the horizontal direction, I can select points in a given x-y plane before calling hscat().  For the vertical direction, I can do a de facto selection by limiting the maximum lag distance to something smaller than the minimum distance between my wells.  

My main interest for this is in 2 directions, horizontal and vertical, but it would be nice to specify angles as in the anis argument for vgm().

Thanks,
Scott Waichler
Pacific Northwest National Laboratory
scott.waichler at pnl.gov