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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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 quasi Posts: 12,067 Registered: 7/15/05
Re: disjunctive constraints in integer linear programming
Posted: Apr 12, 2013 1:39 AM

d.info.sign wrote:
>quasi wrote:
>> d.info.sign 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
more.

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

quasi

Date Subject Author
4/11/13 d.info.sign@gmail.com
4/11/13 quasi
4/11/13 d.info.sign@gmail.com
4/12/13 quasi
4/11/13 William Elliot
4/12/13 RGVickson@shaw.ca
4/12/13 quasi
4/13/13 RGVickson@shaw.ca
4/13/13 RGVickson@shaw.ca
4/14/13 quasi