[Osi] row names ignored in OsiSolverInterface::writeLp

[Dani Pérez]

It didn't work either. I had already tried that one, but setObjName only
sets an OsiSolverInterface attribute which is not used by writeLp :-( Maybe
writeLp should use that attribute instead of getRowName(getNumRows(()) ?

Thanks!

Dani.

On Sat, Oct 8, 2011 at 3:39 PM, Stefan Vigerske <stefan at math.hu-berlin.de>wrote:

> Hi,
>
> does it work if you set the objective name via
>  problem.setObjName ( "obj_func" );
> ?
>
> The warning from CoinLpIO isn't that precise on it, I agree.
>
> Stefan
>
> Am 08.10.2011 10:38, schrieb Dani Pérez:
>
>> Hi,
>>
>> I think I came across an Osi bug or a non-documented behavior of
>> OsiSolverInterface::writeLp.
>>
>> The problem arises when I set all rows and columns' names and I
>> use setIntParam (OsiNameDiscipline,2). I get the following error in
>> writeLp
>> (with Osi compiled with --enable-debug):
>>
>> Coin3007W ### CoinLpIO::is_invalid_name(): Name is empty
>> Coin3007W ### CoinLpIO::are_invalid_names(): Invalid name: vnames[1]:
>> (null)
>> Coin3007W ### CoinLpIO::**setLpDataRowAndColNames(): Invalid row names
>> Use getPreviousNames() to get the old row names.
>> Now using default row names.
>>
>>
>> I've been debugging it a bit and it seems that writeLp expects the
>> objective
>> function name to be stored in the names vector at position getNumRows()
>> (as
>> stated in documentation<https://**projects.coin-or.org/Osi/**
>> browser/trunk/Osi/src/Osi/**OsiSolverInterface.hpp?rev=**1811#L892<https://projects.coin-or.org/Osi/browser/trunk/Osi/src/Osi/OsiSolverInterface.hpp?rev=1811#L892>
>> >
>>
>> indeed).
>> Nevertheless, adding setRowName ( getNumRows(), "obj_func_name" ) won't
>> fix
>> it.
>>
>> The problem seems to be that setRowName will
>> check<https://projects.coin-**or.org/Osi/browser/trunk/Osi/**src/OsiGlpk/
>> **OsiGlpkSolverInterface.cpp?**rev=1811#L3417<https://projects.coin-or.org/Osi/browser/trunk/Osi/src/OsiGlpk/OsiGlpkSolverInterface.cpp?rev=1811#L3417>
>> >if
>>
>> the index is greater or equal to getNumRows() and then silently
>> return,
>> in contradiction with the documentation. Is my understanding wrong? Is
>> there
>> another way to set the objective function name and get rid of the message?
>> Did I hit a bug?
>>
>> Thanks,
>>
>> Dani.
>>
>> PS: I attach the code reproducing the problem with the compilation line on
>> top of the file. I'm using Osi-0.105, a source release dating back to 21
>> September 2011. The trunk code seems to behave similarly but I didn't
>> check
>> it. I'm using OsiGlpkSolverInterface (I didn't try other solvers)
>>
>>
>>
>>
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>
>
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