Re: [Bug-glpk] [Fwd: glpk terminating abnormally]

[Heinrich Schuchardt]

Hello Marc,

the current version of GLPK is 4.53.

> Do you have any recommendations on how to deal with
> this situation ?
Upgrade to the current version.

Can you reproduce the problem with 4.53?

Best regards

Heinrich Schuchardt

On 19.03.2014 21:54, Andrew Makhorin wrote:
> -------- Forwarded Message --------
> Subject: glpk terminating abnormally
> Date: Wed, 19 Mar 2014 15:36:09 -0400
>
> Hello everyone,
>
> We have been using the GLPK software in our statistical system for over
> 10 years now and it is working very well for us, thank you for this
> excellent product!  We are using GLPK 4.07 for the LP component in one
> of our systems written in C and we have come up with a strange result.
>
> In this particular problem, it appears we have numerical instability ,
> which calls the spx_prim_feas() function, then it is triggering a call
> to the insist function as shown below, which causes the system to
> terminate abnormally.  It appears that at one point, in our LP problem,
> the spx->p has a zero value.
>
>  From source program glpxpx2.c
>
> /* the sum of infeasibilities can’t be negative, therefore the modified
> problem can’t have unbounded solution */
> Insist(spx->p != 0);
>
> Is anyone aware if this part has been modified in one of the more recent
> versions of glpk ?  Do you have any recommendations on how to deal with
> this situation ?
>
> Best regards,
> Marc Thomson