[Cbc] Slow model building using CLP

[Haroldo Gambini Santos]

Hi Kevin,

Why to /build/ a model do you need to /modify/ coefficients ? Would it 
be faster to remove a group of constraints (the ones with modified 
coefficients) and then  add a new group of constraints ?

One nice way to quickly add a group of constraints/variables in the 
model is the use of a  CoinBuild object: calls are made first to this 
object and then this object is passed as a parameter in OsiSolverInterface.

Cheers,

Haroldo

On 22-06-2015 12:07, Kevin van Blokland wrote:
> Dear CBC community,
>
> We experience a very slow model creation. We are using 
> the OsiClpSolverInterface in combination with modifyCoefficient to 
> construct our models.
> The construction of the model takes more than 10 minutes, while the 
> solve time is less than a minute.
> Probably we are doing something wrong and we would like to know what 
> is the best way to add variables and constraints and set their 
> coefficients from scratch.
> Could we reserve the dimensions in the packedmatrix?
>
> Best regards,
>
> Kevin van Blokland
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-- 
==================================================
Haroldo Gambini Santos
D.Sc, Computer Science
Universidade Federal de Ouro Preto
http://www.decom.ufop.br/haroldo/

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