[Dip] help with wedding example in dippy

[Ted Ralphs]

Hi Hugh,

All the reported issues are fixed in trunk. The was an additional problem
with the wedding example when using the Python subproblem solver, which was
that it was returning a list of variable-value pairs rather than a
dictionary. This change in interface happened a while back and the example
never got updated. Now it seems everything is working.

I'll merge all these fixes into stable/0.92 a bit later along and work on a
new release. Thanks again!

Cheers,

Ted

On Tue, Nov 10, 2015 at 7:02 PM, Ted Ralphs <ted at lehigh.edu> wrote:

> Hi Hugh,
>
> Thanks for uncovering and reporting these issues. Apparently, my testing
> was not enough to catch these bugs. The immediate cause of the problem with
> the wedding problem is that the last line of the function that solves the
> relaxed problem is mis-indented---it shouldn't be in the for loop.
> Correcting that problem exposes another bug, though. Dippy does not
> currently allow the possibility of not returning any solutions when
> claiming that the problem was solved exactly (i.e., when returning
> DipSolStatusOptimal). Even after fixing those two issues, I'm still seeing
> some possibly buggy behavior with in the subproblem solver itself (in
> wedding.py). All of this should be relatively quick and easy to fix (I
> hope).
>
> The problem in the facility location example seems to be a live example of
> the bug pointed out by Marcus a few days ago, which is also easy to fix. I
> should be able to get all of this fixed and pushed to trunk tomorrow.
>
> Cheers,
>
> Ted
>
> On Mon, Nov 9, 2015 at 11:46 AM, Hugh Medal <hugh.medal at msstate.edu>
> wrote:
>
>> When I run Dip/src/dippy/examples/wedding/wedding.py (on Mac OS X in
>> eclipse with homebrew python using Dip 0.92.1) I get the following
>> exception:
>>
>>
>> COIN Exception [ Error calling method prob.Error returned from _dippy
>>
>> Error in solveRelaxed
>>
>> 'NoneType' object is not iterable
>>
>> solveRelaxed() ] at src/dippy/DippyDecompApp.cpp:L337 in
>> DippyDecompApp::solveRelaxed
>>
>> Traceback (most recent call last):
>>
>>   File
>> "/Users/hm568/Documents/workspace/TestProject2/src/wedding/wedding.py",
>> line 117, in <module>
>>
>>     'generateInitVars' : '1',
>>
>>   File "build/bdist.macosx-10.11-x86_64/egg/coinor/dippy/dippy.py", line
>> 149, in Solve
>>
>>   File "build/bdist.macosx-10.11-x86_64/egg/coinor/dippy/dippy.py", line
>> 865, in solveRelaxed
>>
>> coinor.dippy.dippy.DipError: Error in solveRelaxed
>>
>> 'NoneType' object is not iterable
>>
>>
>> Any help is appreciated.
>>
>>
>> Thanks,
>>
>> Hugh
>>
>> --
>> *Hugh Medal*
>> Assistant Professor
>> Industrial and Systems Engineering
>> Mississippi State University
>> Office: 260K McCain
>> Office: 662-325-3923
>> Email: hmedal at i <hmedal at uark.edu>se.msstate.edu
>> Website: hm568.ise.msstate.edu
>> Office hours: hughmedal "dot" youcanbook "dot" me
>>
>> _______________________________________________
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>>
>
>
>
> --
> Dr. Ted Ralphs
> Professor, Lehigh University
> (610) 628-1280
> ted 'at' lehigh 'dot' edu
> coral.ie.lehigh.edu/~ted
>



-- 
Dr. Ted Ralphs
Professor, Lehigh University
(610) 628-1280
ted 'at' lehigh 'dot' edu
coral.ie.lehigh.edu/~ted
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