Model.cbGetNodeRel()


Model.cbGetNodeRel()

cbGetNodeRel ( vars )

Retrieve values from the node relaxation solution at the current node. Note that this method can only be invoked when the where value on the callback function is equal to GRB.Callback.MIPNODE, and GRB.Callback.MIPNODE_STATUS is equal to GRB.OPTIMAL (see the Callback Codes section for more information).

Arguments:

vars: The variables whose relaxation values are desired. Can be a variable, a matrix variable, a list of variables or matrix variables, or a dict of variables.

Return value:

Values for the specified variables in the node relaxation for the current node. The format will depend on the input argument (a scalar, an ndarray, a list of values or ndarrays, or a dict).

Example usage:

  def mycallback(model, where):
    if where == GRB.Callback.MIPNODE:
      print(model.cbGetNodeRel(model._vars))

  model._vars = model.getVars()
  model.optimize(mycallback)