Memory pig?? Problem with kron function

W = kron(inv_covariance,I);
??? Out of memory. Type HELP MEMORY for your options.
Error in ==> kron at 34
 K = A(ia,ja).*B(ib,jb);

inv_covariance = 11*11 double, I = ones(598,598)

I ran this code on Tuesday, totally worked. But since yesterday, failed to run.

>> memory
Maximum possible array:             200 MB (2.095e+008 bytes) *
Memory available for all arrays:    587 MB (6.157e+008 bytes) **
Memory used by MATLAB:              331 MB (3.468e+008 bytes)
Physical Memory (RAM):             3774 MB (3.957e+009 bytes)

• Limited by contiguous virtual address space available. Limited by virtual address space available.

I think there is enough space (Java heap space 943 MB) and tech support helped me to run this code on other computers that have the same operation system as mine and the code worked.

Does this occur to anyone before? Any suggestions? Thanks in advance!

Answer 1

[Oleg Komarov]

Your W will be around 300 MB and yes it is a common problem.

Any solution is not infinitely scalable in practice due to constraints:

• memory (RAM).
• time.

1106 - Memory Management Guide

[Zoe Zhang]

Thanks. So I have no options but give up running this function on this computer?

[Zoe Zhang]

The java heap space is not the more the better? I was also using 128M then I was suggested by tech support to increase it to the maximum...

Thanks!

[Oleg Komarov]

It depends what you need it for...I use a rule of thumb (sorry not literate here). If I were to get too often java errors in the cmd window I would increase the heap space.

[Zoe Zhang]

I see. Thanks~ :)

Answer 2

[Daniel Shub]

Have you tried rebooting? You have 4 GB of RAM, MATLAB is using 331 MB, but can only find 587 MB free.

[Zoe Zhang]

No, sadly I know little about that. I know it can be done by running msconfig. Then I don't know which to choose and I am afraid that the computer will be restored back to factory settings. Do you know how? Thanks~~

[Oleg Komarov]

Reduce the Java heap space, I have the standard 128 MB. Also, what system are you running, how many applications do you have at startup?

Answer 3

[Sean de Wolski]

Can't you just open the task manager and look at what's using what? Close the program using the most memory... 300Mb of RAM is small for most of today's computers. You could also look at using Matt J's KronProd class which skips the full expansion.

FEX:KronProd

[Zoe Zhang]

I am definitely not a PC export :(

I am actually not running any other programs. But I followed this link

http://www.mathworks.com/support/solutions/en/data/1-4M4ZNT/index.html

and now problem solved! Thanks :)

[Sean de Wolski]

Looking into using KronProd, if you have many of these computations to do, is still probably worth your time.

[Zoe Zhang]

I will for sure, thank you :)

Answer 4

[Zoe Zhang]

I increased the memory allocated to MATLAB R2011a by using the steps at the following link resolves the issue:

http://www.mathworks.com/support/solutions/en/data/1-4M4ZNT/index.html

>> memory
Maximum possible array:            1023 MB (1.072e+009 bytes) *
Memory available for all arrays:   1637 MB (1.717e+009 bytes) **
Memory used by MATLAB:              306 MB (3.213e+008 bytes)
Physical Memory (RAM):             3774 MB (3.957e+009 bytes)

*  Limited by contiguous virtual address space available.
** Limited by virtual address space available.

Now the code runs :) Thanks everyone!