## Efficient cube writing

The default cube order (.lmv) is efficient in terms of disk access, even for writing it at once or by slices. However, if you want to produce a .vlm cube (for e.g. reuse with FILE IN myfile.vlm), you should:

- give XY_MAP the right to allocate as much as memory as possible. If it can, the command will buffer the whole .vlm cube before writing it all at once at the end,
- if the problem still does not fit in memory, you must produce first the .lmv cube and then transpose it (XY_MAP does not support writing a .vlm cube by slices).

This can be achieved with the commands:

    LAS> SIC LOGICAL VOLATILE_MEMORY 90%
    LAS> XY_MAP myfile  ! Will produce myfile.lmv
    LAS> TRANSPOSE myfile.lmv myfile.vlm 312