pack (MATLAB Function Reference)

pack	Examples See Also

Consolidate workspace memory

Syntax

pack
pack filename

Description

pack

frees up needed space by compressing information into the minimum memory required. You must run pack from a directory for which you have write permission.

pack filename

accepts an optional filename for the temporary file used to hold the variables. Otherwise it uses the file named pack.tmp. You must run pack from a directory for which you have write permission.

Remarks

The pack command does not affect the amount of memory allocated to the MATLAB process.You must quit MATLAB to free up this memory.

Since MATLAB uses a heap method of memory management, extended MATLAB sessions may cause memory to become fragmented. When memory is fragmented, there may be plenty of free space, but not enough contiguous memory to store a new large variable.

If you get the Out of memory message from MATLAB, the pack command may find you some free memory without forcing you to delete variables.

The pack command frees space by:

Saving all variables on disk in a temporary file called pack.tmp.
Clearing all variables and functions from memory.
Reloading the variables back from pack.tmp.
Deleting the temporary file pack.tmp.

If you use pack and there is still not enough free memory to proceed, you must clear some variables. If you run out of memory often, you can allocate larger matrices earlier in the MATLAB session and use these system-specific tips:

UNIX: Ask your system manager to increase your swap space.
VAX/VMS: Ask your system manager to increase your working set and/or pagefile quota.
Windows: Increase virtual memory by using System Properties for Performance, which you can access from the Control Panel.

Examples

Change the current directory to one that is writeable, run pack, and return to the previous directory.

cwd = pwd;
cd(tempdir);
pack
cd(cwd)