Geografic-Information-System/scripts/r.drain/tests/testascii_nc.asc

north:      220600
south:      220000
west:       638300
east:       639000
rows:       6
cols:       7
null:       -9999
20 19 17 16 17 16 16
18 18 24 18 15 12 11
22 16 16 18 10 10 10
17 15 15 15 10 8  8
24 16 8 7 8 0 12
17 9 8 7 8 6 12