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<div class="moz-cite-prefix">Fang,<br>
<br>
The way it is meant to work is that you only have the one object -
but it creates many branches. It should look at current solution
and create a branching object which fixes a list down one way and
another the other way. <br>
<br>
I tested on air04 and it did not branch using integers once. It
is useful to have the integers for heuristics etc. Without cuts
and heuristics it is slow.<br>
<br>
To get maximum benefit you might want to derive a class from
CbcFollowOn which knows more about your problem. I think the
implementation just finds row with most non-integral values and
then finds another row to do the branching on.<br>
<br>
The code has not been looked at for many years - so if you do use
it with cuts, I may have to check that the code does not confused
by the extra rows.. <br>
<br>
John Forrest<br>
On 09/06/15 17:05, Fang Ma wrote:<br>
</div>
<blockquote
cite="mid:CABjWwQHpNj6e04fGp_75A37aB_kWdN9yNQVDf_ewcUGpzOMMmg@mail.gmail.com"
type="cite">
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<div>Hi John, </div>
<div><br>
</div>
<div>Thanks for your reply. Actually what I want is to have
follow-on branching all over the branch-and bound tree. </div>
<div><br>
</div>
<div>In that crew example, there is only 1 follow-on object
created. So even if we set it with high priority, we can do
the branching at the root node. Then we rely on integer
variable branching.</div>
<div><br>
</div>
<div>So if I create 200 follow on objects in that example, I
think it still do the follow-on branching at the root node?
but with 200 candidates to choose from. Actually I have set
the number of follow-on branching to 200, there is memory
issue there. </div>
<div><br>
</div>
<div>What I want is to create multiple follow on branching among
the tree and try to minimize the use of single variable
branching (best to avoid it). </div>
<div><br>
</div>
<div>Sincerely</div>
<div><br>
</div>
<div>Fang</div>
<div><br>
</div>
<div><br>
</div>
<div>Fang,
Why do you want to remove the integer objects? Is there
something odd in your problem, which means variables can take
non-integral values?
The integer variables are at lower priority so will only be
branched on as a last resort.
John Forrest
On 03/06/15 05:24, Fang Ma wrote:
><i> Hi CoinOR Cbc community,
</i>><i>
</i>><i> Just a simple question, I am looking at Cbc
crew.cpp example, which </i>><i> revolve around
follow-on branching plus simple binary branching on </i>><i>
integer.
</i>><i>
</i>><i> How to deactivate the variable branching such that
there is only </i>><i> follow-on branching without
simple variable branching ? It seems in </i>><i> the Cbc
source code, the simple integer object was created by
default. </i>><i> After finished branching on follow on
objects, the crew example switch </i>><i> to variable
branching.
</i>><i>
</i>><i> Thanks
</i>><i>
</i>><i> Fang
</i>><i>
</i>><i>
</i>><i> -- </i>><i> Best Regards,
</i>><i> Fang
</i>><i>
</i>><i>
</i>><i>
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<div class="gmail_signature">Best Regards,<br>
Fang Ma<br>
<br>
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