2*(value_at v3d i j 0) - (value_at v3d i j 1)
else
2*(value_at v3d i j (k-1)) - (value_at v3d i j (k-2))
-
- | otherwise =
- let istr = show i
- jstr = show j
- kstr = show k
- coordstr = "(" ++ istr ++ "," ++ jstr ++ "," ++ kstr ++ ")"
- in
- error $ "value_at called outside of domain: " ++ coordstr
where
(dim_i, dim_j, dim_k) = dims v3d