Java Heap Memory Preferences
You can adjust the amount of memory that MATLAB® allocates for Java® objects.
The default heap size is sufficient for most cases.
To adjust the heap size:
On the Home tab, in the Environment section, click Preferences. Select MATLAB > General > Java Heap Memory.
Select a value using the slider or spin box.
Increasing the heap size decreases the amount of memory available for storing data in arrays.
If the amount of memory you specified is not available upon restart, then MATLAB resets the value to the default, and displays an error dialog box. To readjust the value, repeat the previous steps.
If increasing the heap size does not eliminate memory errors, then check your Java code for memory leaks. Eliminate references to objects that are no longer useful. For more information, see Troubleshooting Java SE.