def test_JPT(self):
"""Test Joint Probability Table."""
factors = examples.get_student_CPTs()
bag = Bag('Student', list(factors.values()))
jpt = bag.eliminate(list(bag.scope)).normalize()
self.assertAlmostEqual(jpt.sum(), 1, places=5)
def test_variable_elimination_with_evidence(self):
"""Test the variable elimination algorithm."""
factors = examples.get_sprinkler_factors()
bag = Bag('Sprinkler', factors)
# Compute the (unnormalized) factor over C and A=a1
fC_a1 = bag.eliminate(['C'], {'A': 'a1'})
self.assertAlmostEqual(fC_a1['c0'], 0.12, places=2)
self.assertAlmostEqual(fC_a1['c1'], 0.48, places=2)
def test_as_dict(self):
"""Test serialization."""
factors = examples.get_sprinkler_factors()
bag = Bag('Sprinkler', factors)
bd = bag.as_dict()
self.assertEqual(bd['type'], 'Bag')
self.assertEqual(bd['name'], bag.name)
self.assertEqual(len(bd['factors']), len(bag))
def test_variable_elimination_single(self):
"""Test the variable elimination algorithm."""
# Get the Factors for the Sprinkler network
factors = examples.get_sprinkler_factors()
bag = Bag('Sprinkler', factors)
# Compute the prior over C
fC = bag.eliminate(['C'])
self.assertAlmostEqual(fC['c0'], 0.48, places=2)
self.assertAlmostEqual(fC['c1'], 0.52, places=2)
self.assertAlmostEqual(fC.sum(), 1, places=8)
def test_MAP(self):
"""Test the Bag.MAP() function."""
factors = examples.get_student_CPTs()
bag = Bag('Student', list(factors.values()))
argmax_I = bag.MAP(['I'], {}, False)
self.assertEqual(argmax_I, 'i0')
argmax_G = bag.MAP(['G'], {}, False)
self.assertEqual(argmax_G, 'g1')
argmax_G = bag.MAP(['G'], {}, True)
self.assertEqual(argmax_G[0], 'g1')
self.assertAlmostEqual(argmax_G[1], 0.362)
def test_compute_posterior(self):
"""Test the function Bag.compute_posterior()."""
factors = examples.get_student_CPTs()
bag = Bag('Student', list(factors.values()))
I = bag.compute_posterior(['I'], {}, [], {})
self.assertAlmostEqual(I['i0'], 0.70, places=2)
self.assertAlmostEqual(I['i1'], 0.30, places=2)
S_i1 = bag.compute_posterior(['S'], {}, [], {'I': 'i1'})
self.assertAlmostEqual(S_i1['s0'], 0.20, places=2)
self.assertAlmostEqual(S_i1['s1'], 0.80, places=2)
S_i0 = bag.compute_posterior(['S'], {}, [], {'I': 'i0'})
self.assertAlmostEqual(S_i0['s0'], 0.95, places=2)
self.assertAlmostEqual(S_i0['s1'], 0.05, places=2)
G_I = bag.compute_posterior(['G'], {}, ['I'], {})
self.assertAlmostEqual(G_I['i0', 'g1'], 0.20, places=2)
self.assertAlmostEqual(G_I['i0', 'g2'], 0.34, places=2)
self.assertAlmostEqual(G_I['i0', 'g3'], 0.46, places=2)
s0_i0 = bag.compute_posterior([], {'S': 's0'}, [], {'I':'i0'})
s1_i0 = bag.compute_posterior([], {'S': 's1'}, [], {'I':'i0'})
self.assertAlmostEqual(s0_i0, 0.95, places=2)
self.assertAlmostEqual(s1_i0, 0.05, places=2)
s0G_i0 = bag.compute_posterior(['G'], {'S': 's0'}, [], {'I':'i0'})
self.assertEqual(len(s0G_i0), 3)
def test_variable_elimination_multiple(self):
"""Test the variable elimination algorithm."""
# Get the Factors for the Sprinkler network
factors = examples.get_sprinkler_factors()
bag = Bag('Sprinkler', factors)
# Compute the joint over A and C
fAC = bag.eliminate(['A', 'C'])
self.assertAlmostEqual(fAC['a0', 'c0'], 0.36, places=2)
self.assertAlmostEqual(fAC['a0', 'c1'], 0.04, places=2)
self.assertAlmostEqual(fAC['a1', 'c0'], 0.12, places=2)
self.assertAlmostEqual(fAC['a1', 'c1'], 0.48, places=2)
self.assertAlmostEqual(fAC.sum(), 1, places=8)
def test_scope(self):
"""Test a Bag's scope."""
# Get the Factors for the Sprinkler network
factors = examples.get_sprinkler_factors()
bag = Bag('Sprinkler', factors)
self.assertEqual(bag.scope, {'A', 'B', 'C', 'D', 'E'})
def test_P(self):
"""Test the function Bag.P()."""
factors = examples.get_student_CPTs()
bag = Bag('Student', list(factors.values()))
I = bag.P('I')
self.assertAlmostEqual(I['i0'], 0.7, places=3)
self.assertAlmostEqual(I['i1'], 0.3, places=3)
G_I = bag.P('G|I')
self.assertEqual(G_I.scope, ['I', 'G'])
self.assertEqual(G_I.conditioned, ['G'])
self.assertEqual(G_I.conditioning, ['I'])
I_g1 = bag.P('I|G=g1')
self.assertAlmostEqual(I_g1['i0'], 0.387, places=3)
self.assertAlmostEqual(I_g1['i1'], 0.613, places=3)
def test_repr(self):
"""Test repr(Bag)."""
factors = examples.get_sprinkler_factors()
bag = Bag('Sprinkler', factors)
self.assertEqual(repr(bag), f"<Bag: '{bag.name}'>")