[Coin-lpsolver] What is the best way of getting out N feasible extreme points?

[Yiming Yao]

John,

Our application would not need scaling. It needs to extract the last N 
feasible (extreme) points. I think we can store the first N feasible points 
in a FIFO queue with capacity = N and update the queue with each new 
feasible point along the way to optimality.

Thanks,

Yiming


At 01:12 PM 7/12/2003 -0400, John J Forrest wrote:

>Yiming,
>
>I am not sure what would be the simplest way to do what you want, but I 
>think the best way will be if I create a new class 
>ClpSimplexMessageHandler inheriting from CoinMessageHandler.  This would 
>have a pointer to simplex information plus a void pointer for user.  Then 
>when certain messages occur you could copy solution or basic information 
>across.  This would have more general uses than your particular 
>need.   There are some issues like what happens if scaling is on.
>
>If you give me more details then I can use that as part of the unit test, 
>and I can probably address scaling issue.
>
>On your other question - Presolve obviously gets rid of redundant rows but 
>it may do too much.  Coding in ClpSimplex::tightenPrimalBounds identifies 
>many redundancies (but does nothing about them as it is not going to take 
>them out).  It would be simple to write something to create a new model 
>without those rows.
>
>John Forrest

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