[SCIP] Pysciptop Separator Depth

[Christopher Hojny]

Dear Kody,

Next to the frequency parameter, separators also feature the parameter 
"expbackoff", which provides the base for exponential increase of 
frequency at which the separator is called. The default value of 
"expbackoff" is 4, which means that your separator is called at depth 
levels 4^i as observed by you. By setting

    model.setParam("separating/<your separator's name>/expbackoff", 1)

your separator should be called at every node of the branch-and-bound tree.

Best regards,
Christopher


On 09-05-2025 17:54, Kody Kazda wrote:
> 	
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> 
> Hi SCIP team,
> 
> I have written a separator using pysciptop includeSepa:
> 
> model.includeSepa(myseparator, priority = 1E8, freq = 1)
> 
> Based on the SCIP documentation, SEPAEXECLP callback method should run 
> at every node based on freq being set to 1.
> 
> However, when I simply print the node depth within SEPAEXECLP:
> 
> print(self.model.getCurrentNode().getDepth())
> 
> I notice that the following depths are printed during the BB search:
> 
> 0,1,4,16,64
> 
> I would have expected 0,1,2,3,4…
> 
> Can anyone help explain this behaviour?
> 
> Thank you!
> 
> Kody
> 
> 
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