[Coin-discuss] Making changes to coefficients in existing rows in OSI

[John J Forrest]

Stuart,

Try building model as a CoinModel and use
OsiSolverInterface:loadFromCoinModel.  CoinModel allows for more
lightweight modification of model.

You will see an artificial usage in Test/OsiClpSolverInterfacetest.cpp

John Forrest


                                                                           
             "Thorncraft,                                                  
             Stuart"                                                       
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             org                       [Coin-discuss] Making changes to    
                                       coefficients in existing rows in    
                                       OSI                                 
             01/04/06 08:54 PM                                             
                                                                           
                                                                           
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Hi

I’ve been using the OSI CLP interface to construct and solve the same
optimisation problem repeatedly but with different row bounds, column
bounds and decision-variable coefficients.  I’d like to be able to do this
by making only minor changes to the existing optimisation rather than
regenerate the problem completely from scratch.

I note that the “setColBounds” and “setRowBounds” methods can be used for
changing the bounds on existing columns or rows but could not find a
similar method that can be called to change decision variable coefficients.

So my question is what is the best way to make changes to decision-variable
coefficients using OSI?  E.g. does a method exist to do this or is it
necessary to delete the relevant row(s) and recreate them?

Apologies if I’ve missed something in the OSI interface.

Thanks
Stuart



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