[Cbc] Cut management

[Giacomo Nannicini]

Hi,
I recently posed some questions on cut management to John Forrest. I
am posting you the question and the answer he gave me, as I think
that some of you will find it interesting.

Question:

What I understood from the code is that all cutting planes which are
not active in any node are removed from the cut pool. This means that
if I generate some cuts at the first pass at the root node, all those
which are not active will be immediately removed from the cut pool. Is
this correct? Or are cuts removed only if they have been inactive for
several iterations?
Is there a limit to the size of the cut pool, and if there is, what is
the criterion to choose the cuts that should be removed/replaced by
new ones?


Answer:

There is no limit on cut pool size. Cuts marked as global are never
removed. The reference to a local cut is removed at a node if goes slack.
If the count of references reaches zero then the cut itself is removed.



Giacomo