[Coin-symphony] tracking cuts

[Michael Hennebry]

On Wed, 13 Jul 2005, Ted Ralphs wrote:

> Yes, that is the idea of the global pool, but the pool is not checked
> every iteration by default (this is configurable) and it is not checked
> until after user_is_feasible() is called in the LP processing loop.
> Furthermore, cut generation is still performed, even when the pool is
> checked. For classes of inequalities for which there is an exact
> separation algorithm (such as subtour constraints), this means that the
> pool will not have any effect because any violated cuts previously
> generated will be re-generated by the cut generation routines before
> they are found in the pool. Generally speaking, one should not store
> cuts that are "easy" to re-generate in the pool. In particular, this
> includes any class for which there is efficient exact separation. For
> classes that are difficult to separate or for which only heuristic
> separation is possible, the pool will be much more effective. Hope this
> helps. Let me know if you find out there really is a bug in there somewhere.

As I understand the above, the sequence is
check feasibility
generate cuts
fetch cuts from pool.

Correct?

-- 
Mike   hennebry at web.cs.ndsu.NoDak.edu
"There are three kinds of people,
those who can count and those who can't."