Re: [Help-glpk] Execution time

[Oscar Gustafsson]

Alessandra,

it is not an unreasonable long time for such a big problem. You can find 
problems with much fewer rows and columns that are practically impossible 
to solve using branch-and-bound.

The MIP-solver got a big upgrade starting from version 4.9, so if you are 
using 4.8 you will most likely not use it (unless you are infact using a 
later GLPK but a 4.8-interface, however even then you will not be able to 
access lpx_intopt, which is the new solver).

So, start by upgrading the GLPK-version and try the advanced MIP-solver as 
a first step.

Good luck!

/Oscar Gustafsson


On Fri, 14 Sep 2007, Alessandra De Luca wrote:

> I'm trying to solve a MIP problem with 17575 rows, 14960 column and 1018925 
> non-zeros but Glpk spend a lot of time to solve it (about 40 minutes)....it's 
> normal or there is a way to solve the problem quickly by setting some 
> parameters (for example I've realized that if I set the parameter lpx_k_branch 
> to 0  the execution time for the same problem become larger than 12 hours)?
>  In this case what are the parameters I have to set to improve glpk solver and 
> so to reduce the execution time?
>  (I'm using glpk from my java code by using Glpk 4.8 java interface).
>
>  Thanks
>
>
> ---------------------------------
>
> ---------------------------------
> L'email della prossima generazione? Puoi averla con la nuova Yahoo! Mail