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Topic: disjunctive constraints in integer linear programming
Replies: 9   Last Post: Apr 14, 2013 2:43 AM

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Posts: 12,067
Registered: 7/15/05
Re: disjunctive constraints in integer linear programming
Posted: Apr 12, 2013 1:39 AM
  Click to see the message monospaced in plain text Plain Text   Click to reply to this topic Reply wrote:
>quasi wrote:
>> wrote:
>> >
>> >I have an integer linear programming problem as follows:
>> >
>> >The constraints are either
>> >
>> >x >= 0
>> >y = u
>> >z = x + v
>> >
>> >or
>> >
>> >x < 0
>> >y = u - x
>> >z = v
>> >
>> >where y, z, u, v range over non-negative integers.
>> >
>> >There are other unrelated constraints associated with
>> >u, v, y, z.
>> >
>> >What's the most simple way to encode the disjunctive case?

>>Why not just run two separate linear programs and choose
>>whichever of the two optimal solutions offers a better value
>>for the objective function?

>Unfortunately we can't. This form of constraints occur often
>in our system. The approach you suggested would lead to
>exponential enumeration.

Why would there be exponential explosion? I see times 2, nothing

Can you give a complete example with all variables, constraints
and the objective function specified?


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