[GAP Forum] [GAP Support] Regarding GAP Error

[Hulpke,Alexander]

Dear Forum, Dear Manohar Choudhary,

> 
> When we run a large number of calculations GAP  show following error but
> Small calculation My same code work fine.
> How I increase  my GAP pre set memory limit?
>  Please Help me.
> Error is following and Screenshot is attached.
> 
> 
> Error, reached the pre-set memory limit
> (change it with the -o command line option) in
>  tups := [ tup ]; at /proc/cygdrive/C/gap-4.10.2/lib/list.gi:2746 called
> from
> Cartesian2( list, n, tup, i + 1 ) at /proc/cygdrive/C/gap-4.10.2/lib/
> list.gi:2751 called from

Please see FAQ 6.2:

https://www.gap-system.org/Faq/faq.html#6.2

on how to deal with memory limits (your error message corresponds to the "exceeded the permitted memory (-o command line option)" error listed there.)

Given that the error happens in the calculation of a cartesian product, I suspect that you are asking for the creation of an unneccessarily large object:

- Can you estimate before-hand how many elements would be in the product you calculate? How much memory would it take? Is this a plausible calculation for the computer you have?
- Could you replace the creation of a full cartesian product by iterated for-loops over smaller products -- i.e. test product elements as soon as they are created, instead of storing all?

Regards,

  Alexander Hulpke

-- Colorado State University, Department of Mathematics,
Weber Building, 1874 Campus Delivery, Fort Collins, CO 80523-1874, USA
email: hulpke at colostate.edu, 
http://www.math.colostate.edu/~hulpke