Re: [Help-glpk] Can GLPK use multiple object?

[Marcin Mucha]

It seems to me that in this particular case (but not in general) you
can get away
with an ordinary LP using the method you suggested.
By putting Y <= Z1 and Y <= Z2 in the program instead of Y=min(Z1,Z2), you
only guarantee that Y <= min(Z1,Z2). However, in the optimal solution you will
have Y = min(Z1,Z2), because any smaller value would mean an unnecessarily
large value for X because of the first constraint.

Marcin

On Tue, Jul 20, 2010 at 11:36 PM, xiaomi <address@hidden> wrote:
> No. Not their sum. For example this problem:
>
> Object: minimize X
> Constraint:  X+Y>=8, Y=min(Z1,Z2) Z1=...., Z2<.....
>
> Do I describe Y as "Y<=Z1, Y<=Z2" ?  That is not correct unless I maxmize Y
> in my object at the same time as minimizing X. So I asked whether multiple
> objects are functional.
>
>
>
>
>
> Mansour Moufid :
>>
>> 2010/7/20 xiaomi <address@hidden>:
>>
>>>
>>> I am running a project that need to minimize more than one variable in
>>> LP solver. Can GLPK do that? If yes, how to do so?
>>>
>>
>> Minimize their sum?
>>
>>
>
>
> _______________________________________________
> Help-glpk mailing list
> address@hidden
> http://lists.gnu.org/mailman/listinfo/help-glpk
>



-- 
Dwell not on close decisions, and thus, when you play against
dwellers, you will make reciprocal gains in energy conservation and
sanity preservation.

Tommy Angelo