[SCIP] Scip and pricer

[Stephen J Maher]

Hi Luca,

To solve your problem by column generation using SCIP you must implement 
a variable pricer. There are two fundamental callbacks for a variable 
pricer, PRICERREDCOST and PRICERFARKAS. Descriptions of the fundamental 
callbacks are given in http://scip.zib.de/doc/html/PRICER.php.

Taking the PRICERREDCOST as an example, what must occur in this callback 
is: identify whether a variable exists with negative reduced cost; if 
one exists, then add that variable to the master problem. The way to 
identify whether a variable with negative reduced cost exists is purely 
up to you. As such, it is possible to execute algorithms that are 
implemented in external libraries to perform this task.

What I would suggest is to write a header file containing all 
declarations related to the pricer that you have already implemented in 
C. Then you can include this header file in the variable pricer that you 
write for your SCIP implementation. This will allow you to call your own 
variable pricer from within the PRICERREDCOST callback to identify 
variables with negative reduced cost.

Cheers,

Steve

On 07/10/15 12:42, Luca Mencarelli wrote:
> Dear SCIP user,
>
> I want to implement a column generator in SCIP and I have already
> the pricer implemented in C. Since the pricer is quite complicated,
> I would ask you if there is a way (and what I need) to create an
> interface between the price routine and SCIP, without explicetly
> implement, for instace, the static method SCIP_RETCODE initPricing.
>
> Thanks in advance,
> Luca
>