[Osi] [Clp] set row solution (activities)

[Ted Ralphs]

The row activity is determined by the column solution, so how could it
make sense to set it independently?

Ted

2009/8/13 Matthew Galati <magh at lehigh.edu>:
> Why not just add a method to ClpModel that sets rowActivity_ and then a method to OsiClp that sets row solution?
>
>
>
>> Disgusting solution but you could create a class that inherits from clpsimplex, provides functions to set rowactivity (protected) and cast to it.
>>
>>
>>
>> From: clp-bounces at list.coin-or.org [mailto:clp-bounces at list.coin-or.org] On Behalf Of Matthew Galati
>> Sent: Thursday, August 13, 2009 5:14 PM
>> To: Lou Hafer
>> Cc: osi at list.coin-or.org; clp at list.coin-or.org
>> Subject: Re: [Clp] [Osi] set row solution (activities)
>>
>>
>>
>> I think setRowPrice sets the dual solution - not the (primal) row solution.
>>
>> Internally, it is the rowActivity_ array that needs to be set - that is what is returned by getRowActivity(). That is why you are not seeing it come back - you are actually setting the duals with setRowPrice.
>>
>> I am not sure what it does to internals, but I think all you need is a method "setRowSolution" and do a memcpy into rowActivity_.
>>
>>
>>
>>
>> Matt,
>>
>>        Osi.setColSolution and Osi.setRowPrice will set the column and row
>> solution, respectively.  Row activity should follow from setColSolution.
>>
>>        Based on the Osi unit test, OsiClp ignores imposed row and column
>> solutions (at least, they are not immediately reflected in the results returned
>> for row activity and reduced costs).
>>
>>                                                Lou
>>
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>>
>
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-- 
Dr. Ted Ralphs
Associate Professor, Lehigh University
(610) 628-1280
ted 'at' lehigh 'dot' edu
coral.ie.lehigh.edu/~ted