[OS] multiple solutions

[Horand Gassmann]

Mike Steglich <mike.steglich at berlin.de> wrote:

> Is it possible to write the incumbents found during an MIP  
> optimization into a OSrL file?

Yes. :-)

There are several routes you might want to take. First, you can put  
multiple <solution> elements into the file. Each solution must have a  
status; you could use "bestSoFar" for the incumbent solutions.

Alternatively you might want to look at <other> elements that somehow  
code the incumbent solution appropriately. You'd need to choose your  
own name for the <other> elements, and I am not sure off-hand how you  
could capture the objective value in the same element. (But you could  
always compute that on the fly if needed.)

Or you can simply print out the incumbents in the solver, and capture  
the solver output in the <job> option. Our OSrL parser can put any of  
those versions into an in-memory OSResult object, although the  
interpretation of what the different things mean would be up to you  
--- at least at this point. Our current repository has an osol file,  
serverOutputCapture.osol, and an osrl file, serverOutputCapture.osrl,  
to illustrate.

Hope that helps.

gus

> Thanks,
>
> Mike
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Horand I. Gassmann, Professor

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