[Fwd: Re: [Help-glpk] GLPK 4.8 preferences]

[Brady Hunsaker]

I accidentally sent a reply only to the poster, but I meant it to go to
the list:

-------- Original Message --------

There are no artificial limits on the size of instances that GLPK can
handle.

The amount of available memory provides one limit to the size of the
instance that you can load.  For an LP, I think this is the main limit.
 For an IP, it is more complicated since it depends on how many nodes of
the branch-and-bound tree are active at one time.  This depends on the
structure of the instance, but the number of integer variables plays a
large role.

Perhaps you mean, "How large a problem can be solved in a reasonable
amount of time?"  This cannot be quantified in numbers of variables and
constraints.  Some instances with 100000 variables are much easier than
other instances with only 1000 variables.  It all depends too much on
the structure of the instance.  If you are dealing with a particular
type of instance then you may be able to say something, but I think you
will have to actually try a bunch of those instances to find your
"limit", and it will depend on your definition of "reasonable amount of
time".

What is the reason that you want to know a limit?  If you're wondering
about particular instances, just try them and see.

Brady

Grzegorz Nowak wrote:
> Hi,  
>  
> I have searched everywhere for information about how big problems the
> glpsol tool version 4.8 can manage. I found that version 4.3 could
> manage 100.000 constraints and 1000 variables. I don't think this is
> true for version 4.8. In an university project I developed an problem
> with 1680 variables, and it could be solved within reasonable time.
> Where can I find any information about this topic? Any help is
> appreciated.
>  
> Thank you
>  
> Grzegorz Nowak
> 
> p.s. I have also searched all the GLPK documentation without any luck
> 
> 
> _______________________________________________
> Help-glpk mailing list
> address@hidden
> http://lists.gnu.org/mailman/listinfo/help-glpk


-- 
Brady Hunsaker
Assistant Professor
Industrial Engineering
University of Pittsburgh
http://www.engr.pitt.edu/hunsaker/


-- 
Brady Hunsaker
Assistant Professor
Industrial Engineering
University of Pittsburgh
http://www.engr.pitt.edu/hunsaker/