Re: [Help-glpk] Embedding GLPK to user application

[Axel Simon]

On Oct 26, 2008, at 9:15, <address@hidden> wrote:

> Hello!
>
>
>
> I try to embed  #8220;GLPK-solver #8221;
> to user application. The main problem is the application #8217;s   
> #8220;hanging
> up #8221; during solution process. User what to see solving  
> progress and view best
> feasible solution during solving process in his GUI application.  
> With  #8220;lp_solve #8221; this problem solved by using callback
> functions. Callbacks raises on each simplex iteration and on each  
> improving solution
> found. Programmer may put his code to callback functions to  
> iteration with user
> (handling mouse, keyboard and windows events) and fetching    
> viewing feasible
> solutions. If callback function return false then solving process  
> is halted. So,
> programmer may supply user by possibilities stop solving process in  
> any moment
> of time.

If you want to give user feedback after each iteration, you could  
also try to limit the number of iterations the solver performs (by  
using the it_lim field of the parameter data structure passed to the  
solver). In principle, by setting the limit to 1, you should get the  
sequence of solutions that the solver examines.

From the top of my head: I tried this tactic to count the number of  
iterations the solver takes to find a solution. It didn't always work  
in the sense that the solver did not always make progress when given  
one iteration to run. I remember that somehow there was an infinite  
loop and I had to give it several iterations to guarantee that it  
terminates. But this might be a starting point.

Cheers,
Axel.