> phh("hex_skew", 3L, nrow = 7, ncol = 9)
/------------------\
| 1 2 3 1 2 3 1 2 3|
|2 3 1 2 3 1 2 3 1 |
| 1 2 3 1 2 3 1 2 3|
|2 3 1 2 3 1 2 3 1 |
| 1 2 3 1 2 3 1 2 3|
|2 3 1 2 3 1 2 3 1 |
| 1 2 3 1 2 3 1 2 3|
\------------------/