Пример #1
0
 def setUp(self):
     # Create BayesNet
     self.bn = BayesianNetwork()
     # Create Nodes
     weather0 = DiscreteNode("Weather0", ["Sun", "Rain"])
     weather = DiscreteNode("Weather", ["Sun", "Rain"])
     ice_cream_eaten = DiscreteNode("Ice Cream Eaten", [True, False])
     # Add nodes
     self.bn.add_node(weather0)
     self.bn.add_node(weather)
     self.bn.add_node(ice_cream_eaten)
     # Add edges
     self.bn.add_edge(weather, ice_cream_eaten)
     self.bn.add_edge(weather0, weather)
     # Set probabilities
     cpt_weather0 = numpy.array([.6, .4])
     weather0.set_probability_table(cpt_weather0, [weather0])
     cpt_weather = numpy.array([[.7, .5], [.3, .5]])
     weather.set_probability_table(cpt_weather, [weather0, weather])
     ice_cream_eaten.set_probability(.9, [(ice_cream_eaten, True),
                                          (weather, "Sun")])
     ice_cream_eaten.set_probability(.1, [(ice_cream_eaten, False),
                                          (weather, "Sun")])
     ice_cream_eaten.set_probability(.2, [(ice_cream_eaten, True),
                                          (weather, "Rain")])
     ice_cream_eaten.set_probability(.8, [(ice_cream_eaten, False),
                                          (weather, "Rain")])
Пример #2
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#About this example:
#This example shows how approximate inference can be used query a purely continuous
#bayesian network. At first that network is being constructed and afterwards it
#is passed to an MCMC object that is used to answer several kinds of questions:
#-Prior marginal
#-Posterior marginal
#-Probability of evidence
#-Maximum a-posteriori hypothesis


#Construct some simple BayesianNetwork. 

#topology
bn = BayesianNetwork()
cnf=ContinuousNodeFactory()
age = cnf.createExponentialNode("Plant_age")
height = cnf.createGaussNode("Plant_height")
diameter = cnf.createBetaNode("Plant_diameter")
bn.add_node(age)
bn.add_node(height)
bn.add_node(diameter)
bn.add_edge(age,height)
bn.add_edge(age,diameter)



#parameterization
#Semantics: Many young plants and the higher the age the lower the probabilty
#->lambda=2.0
Пример #3
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 def setUp(self):
     self.bn = BayesianNetwork()