problem.addcbnodecutoff
problem.addcbnodecutoff |
Purpose
Declares a user node cutoff callback function, called every time a node is cut off as a result of an improved integer solution being found during the branch and bound search. This callback function will be called in addition to any callbacks already added by addcbnodecutoff.
Synopsis
problem.addcbnodecutoff (f_nodecutoff, object, priority)
f_nodecutoff (my_prob, my_object, node)
Arguments
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f_nodecutoff
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The callback function, which takes three arguments,
my_prob,
my_object and
node, and has no return value. This function is called every time a node is cut off as the result of an improved integer solution being found.
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my_prob
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The problem passed to the callback function,
f_nodecutoff.
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my_object
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The user-defined object passed as
object when setting up the callback with
addcbnodecutoff.
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node
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The number of the node that is cut off.
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object
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A user-defined object to be passed to the callback function,
f_nodecutoff.
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priority
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An integer that determines the order in which multiple node-optimal callbacks will be invoked. The callback added with a higher priority will be called before a callback with a lower priority. Set to 0 if not required.
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Example
The following notifies the user whenever a node is cutoff during the global search:
prob.addcbnodecutoff (Cutoff, None, 0) mipoptimize (prob, "")
The callback function might resemble:
def Cutoff (prob, object, node):
print ("Node {0} cutoff".format (node))
Further information
This function allows the user to keep track of the eligible nodes. Note that the LP solution will not be available from this callback.
Related topics