whats this problem and whats solution?

[Hamed Sahebi]

op. sys. refuses to provide memory
Stata's data-storage memory manager has already allocated 1616m bytes and
it just attempted to allocate another 16m bytes. The operating system
said no. Perhaps you are running another memory-consuming task and the
command will work later when the task completes. Perhaps you are on a
multiuser system that is especially busy and the command will work later
when activity quiets down. Perhaps a system administrator has put a
limit on what you can allocate; see help memory. Or perhaps that's all
the memory your computer can allocate to Stata.

[Clyde Schechter]

The message you got is self-explanatory. Whatever it is you are trying to do requires more memory than is available on your system. The causes for this vary widely, as explained by the message. It may be that what you are doing exceeds the capacity of your computer's memory. Or it may be that other programs running on your system at the same time are "hogging up" the memory and there isn't enough left over for Stata. So it all depends on what you are doing and what else was running on your computer at the time. If you are working on a computer that is attached to some multiuser system, it may also depend on what other users are running at the same time, and it is also possible that the administrators of the system have imposed some limit that your needs exceed.

Potential solutions:

1. If it's your own computer, close down any other applications you are running and try again.
2. If you are on a multi-user system, try re-running the application at a time when the system will be less busy.
3. Try to revise your program so that it uses less memory. The details of this obviously depend on what you are doing. But the easiest steps are to -drop- any variables that aren't absolutely needed for the calculations, and similarly to -drop- any observations that play no role. The -compress- command will reduce each of your variables to the storage type that takes the minimum amount of memory compatible with the information they contain. More complicated approaches may involve using an altogether different algorithm to solve that problem that might use less memory (perhaps at the expense of taking longer to run). For example, some problems can be done with less memory by doing them on "chunks" of the data one at a time and the results then put back together. Without knowing what you're trying to do, it's impossible to say if this is an option, or what particular alternatives to consider.
4. If you're up against a limit imposed by the system administrator and #3 does not solve the problem, you could speak to system administration and request a temporary allocation of extra memory.
5. If the problem is on your own computer and you just don't have enough physical memory, perhaps you can persuade somebody who has a bigger computer to let you run your problem on theirs. Or, you could by more memory chips and install them (assuming your motherboard has slots for this.)