Thanks for the response. To recap... I've got a 4x4 grid of XYZ & conductivity on the sloping side of a lake. I brought the data into DX as a scattered file with a .general header & made an Autogrid of the file. I also have a gridded DEM of the basin bathymetry in DX as a Rubbersheet. The output looks fine except that in places the Autogrid extends beyond the DEM Rubbersheet. Ie. Interpolation extends beyond the basin floor in places.
As a (hopefully) temporary & inelegant fix, I've manually added data with bad flags (where Z > the basin floor) to the .general file, then made the badflags invalid to make the Autogrid "aware" of the bathymetry. Does anyone know of a way to clip an Autogid to an irregular surface (the bathymetry DEM)? ClipPlane and ClipBox don't seem appropriate since the rubbersheet is irregular. The resolution of the Autogrid and the DEM are different - an IF statement on each position using Compute doesn't seem possible (?). Perhaps this isn't the best approach - any alternatives would be greatly appreciated. Thanks, Ted Lewis You should still import as a 4x4 grid. Within DX you can treat the data as grid or scattered -- this way you have the option. For the missing samples put in a "missing" value, which you can flag as invalid with Include, but kept in the field (culling should be off). You can still use Autogrid or Regrid on the scattered points, but you can also do Refine and other operations on the "original" imported grids. FYI, Paul Huang ([EMAIL PROTECTED]) implemented something similar several years ago while helping a group from the NY State environmental agency. Part of their needs was to reconstruct reservoir bathymetry from sample points. He may have some further suggestions.
