Re: [Help-glpk] Objective value issue

[Mattia Buccarella]

Thanks for your answer.
The link you suggested is the one I already saw and discussed in my first email.
My question is about the meaning of "constant", since all the terms in my objective function are functions of variables (i.e.: none of them is actually constant). Also, I would like to know if there is any way not to let this shift happen.

Thank you again for your time.

--

Mattia Buccarella

On Fri, Jul 11, 2014 at 5:35 PM, Heinrich Schuchardt <address@hidden> wrote:

Hello Mattia,

please, read
http://en.wikibooks.org/wiki/GLPK/Troubleshooting#Objective_shift_term_ignored_when_exported

Best regards

Heinrich Schuchardt

http://www.xypron.de

Am 11.07.14 um 17:20 schrieb Mattia Buccarella

> Hello everyone,
>
>
>
> my name is Mattia and I am using glpsol in the development of my master
>
> thesis in computer science.
>
>
>
> I am writing to you all for something I could not find anywhere so far.
>
> When I use glpsol to solve my model (written in MathProg, with separate
>
> data input file), all the variables are configured properly as I expect (I
>
> am referring to a "dummy" input I use to verify the correctness of my
>
> model). Nevertheless, the value of the objective function is shifted and I
>
> get the following message:
>
>
>
> Model has been successfully generated
>

> *glp_mpl_build_prob: row obje; constant term 84384 ignored*

>
> GLPK Integer Optimizer, v4.52
>
> ...etc...
>
>
>
> Searching the web, I found somebody had a similar issue but it was not
>
> related to the objective function and also involved CPLEX (context very
>
> different from mine). Does anybody of you know what is happening? When I
>
> try to solve the model (same model, same input) with COIN-OR Cbc, through
>
> AMPL, it gives me the non-shifted value. Also, it does not tell me anything
>
> about constant terms in the function. Also, I checked again and again my
>
> objective function: all the terms are functions of some variable, so
>
> nothing is really constant in the calculation.
>
>
>
> Thanks in advance for your help.
>
> Goodbye.
>
>
>
> --
>
> Mattia Buccarella
>

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