Randy, a multigrid will do it for you. Here's how you can create the overlap. Slab the 0->m-1 field in dimension 0, all positions, thickness 0. That'll create a series of m 1-D vertical slices. Now slab the m->2m-1 field in dimension 0, position 0, thickness 0. That'll create a field containing only the first vertical slice of the second grid. Now append the second result onto the first, with id = m. That will create a series with m+1 vertical slices, with series positions 0 through m. Now Stack that, and you'll get a regular grid with X from 0 to m. CollectMultigrid that with the original second grid, and you're done.
Greg (See attached file: randy1.net)
randy1.net
Description: Binary data
