[gecode-users] Linear memory allocation

[Farshid Hassani Bijarbooneh]

On Sep 6, 2011, at 10:04 AM, Christian Schulte wrote:

> Hi,
> 
> 1) The problem here is the number of variables, the number of constraints is
> not that much of an issue. Are they Boolean or integer variables. Boolean
> variables are much smaller. But still it takes too much memory. Could I have
> a look at your model?
The variables are integer with domain 0,1. I had to change to integers at some point due to troubles in implementation of a custom branching. 
> 
> 2) Domain consistent propagation for linear is exponential (that is, here it
> is 2^49) Please read Tip 4.6 in MPG. Maybe MPG should have a big fat warning
> (we had this issue before, that's why the reference doc has a big fat
> warning).
I see, though I still wonder why changing to boolean variables fixes the Domain consistency issue here. I thought integer variables with domain 0,1 are treated the same as boolean despite the memory.
> 
> 2) What does "Gist crashes" mean. It should crash even though propagation
> does not terminate. 
Gist starts but doesn't show the window, and can not be closed unless killing the process.

Cheers,
Farshid 
> 
> Cheers
> Christian
> 
> --
> Christian Schulte, www.ict.kth.se/~cschulte/
> 
> -----Original Message-----
> From: users-bounces at gecode.org [mailto:users-bounces at gecode.org] On Behalf
> Of Farshid Hassani Bijarbooneh
> Sent: Tuesday, September 06, 2011 9:38 AM
> To: users at gecode.org
> Subject: [gecode-users] Linear memory allocation
> 
> Hello,
> 
> I have a model with 10^2 to 80^2 variables and linear constraints over 49
> variables each. We have the following issues:
> 1. The code allocates at least 1Gb of memory for even N=50.
> Changing the recomputation distance (-c-d) doesn't seem to help in this
> case.
> 2. Changing the consistency to Domain (line 187) causes the code to process
> endlessly! (Gist crashes) even for N=20 I suspected the domain consistency
> problem is because of the use of IntVarArray instead of BoolVarArray and
> changing to Bool fixed it, but still very strange that Int gets stuck.
> 
> Please find the code of the isolated problem attached.
>