DESCRIPTION
r.tile retiles an existing raster map with user defined 
x and y tile size.
NOTES
r.tile generates a separate raster for each tile.
This is equivalent to running g.region along with
r.resample in a double loop.
The module can be used to split a large raster map into smaller
tiles, e.g. for further parallelized analysis on a cluster computing
system.
The overlap is defined in rows/columns.
EXAMPLE
Retiling example for the North Carolina DEM:
g.region raster=elevation -p
# rows:       1350
# cols:       1500
# generating 2 x 2 = 4 tiles (width=1500/2, height=rows/2)
r.tile input=elevation output=elev_tile width=750 height=675
SEE ALSO
g.region,
r3.retile
AUTHOR
Glynn Clements