[Scip] Obtaining the LP solution to a node in Branch, Cut and Price

[Tue Christensen]

Hello SCIP subscribers!

I have yet another question. I am during a heuristic in a branch, cut and price algorithm. The heuristic is called at SCIP_HEURTIMING_AFTERLPNODE and obtains a feasible solution from the current optimal LP solution (the nonzero variables to be precise). The question, what is the fastest way to obtain the LP solution of a node?

Currently I find it by going through all the variables added and checking manually by SCIPvarGetSol. This is not very satisfying because of a potentially large number of variables. Also, this might give me the solution the a pseudo solution which should be avoided. Currently if the heuristic detects a pseudo solution (e.g. binary variables with value > 1 or < 0), it simple stops the heuristic.

It seems that the SCIPcreateLPSol, could be a way of doing it. I am, however, not sure how to iterate through the solution to make the required changes for the solution to be feasible. The optimal way would be a call to a function that yields me with an array of the variables nonzero in the current LP along with the number of variables and an array containing their current value. Is there such a function?

Thank you all in advance!

Tue Christensen


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