help

[ОвСЗЦЮ -]

Some parts of this message have been removed. Learn more about Nabble's security policy.

glpsol -m big.mod -o a.log

 

the attached file is model file

 

it seems take too much time to have a
result

 

could anybody help me?

 

Tks a lot





 

glpsol -m big.mod -o a.log

 

the attached file is model file

 

it seems take too much time to have a result

 

could anybody help me?

 

Tks a lot

_______________________________________________
Bug-glpk mailing list
Bug-glpk@...
http://lists.gnu.org/mailman/listinfo/bug-glpk

[Andrew Makhorin]

> glpsol -m big.mod -o a.log

>  

> the attached file is model file

>  

> it seems take too much time to have a
> result

>  

> could anybody help me?

Try:

   glpsol -m big.mod --mir

Using mir cuts the solution takes about 30 secs on my machine.



_______________________________________________
Bug-glpk mailing list
Bug-glpk@...
http://lists.gnu.org/mailman/listinfo/bug-glpk

[Andrew Makhorin]

> Andrew,Tks.really really good.
>
> it takes about 68.9 secs on my machine
>
> I'm not good at maths.
> What's the reason for --mir?

Your instance is hard for the branch-and-bound method used by
default in glpsol to solve mip. Specifying '--mir' option you
enable using the branch-and-cut method, in which case glpsol tries
to generate so called mir (mixed integer rounding) inequalities
(cutting planes) at some nodes of the search tree, that allows
significantly reducing the solution time.

For more details see:
http://en.wikipedia.org/wiki/Branch_and_bound
http://en.wikipedia.org/wiki/Branch_and_cut



_______________________________________________
Bug-glpk mailing list
Bug-glpk@...
http://lists.gnu.org/mailman/listinfo/bug-glpk