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)
G = bag.compute_posterior(['G'], {}, [], {})
self.assertAlmostEqual(G['g1'], 0.3620, places=4)
self.assertAlmostEqual(G['g2'], 0.2884, places=4)
self.assertAlmostEqual(G['g3'], 0.3496, places=4)
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_JPT(self):
"""Test Joint Probability Table."""
factors = examples.get_student_CPTs()
bag = Bag('Student', list(factors.values()))
jpt = bag.variable_elimination(list(bag.scope)).normalize()
self.assertAlmostEqual(jpt.sum(), 1, places=5)
def test_div_cpt(self):
"""Test CPT division."""
CPTs = examples.get_student_CPTs()
I = CPTs['I']
S_I = CPTs['S']
# Dividing a CPT should yield a Factor
SI = S_I.div(I)
self.assertIsInstance(SI, Factor)
def test_mul_scalar(self):
"""Test CPT multiplication with a scalar."""
CPTs = examples.get_student_CPTs()
I = CPTs['I']
S_I = CPTs['S']
# Multiplying a CPT should yield a Factor
Sx3 = S_I.mul(3)
self.assertIsInstance(Sx3, Factor)
def test_mul_cpt(self):
"""Test CPT multiplication with another Factor/CPT."""
CPTs = examples.get_student_CPTs()
I = CPTs['I']
S_I = CPTs['S']
# Multiplying a CPT should yield a Factor
SI = S_I.mul(I)
self.assertIsInstance(SI, Factor)
def test_mul_div(self):
"""Test division after multiplication for equality."""
CPTs = examples.get_student_CPTs()
I = CPTs['I']
S_I = CPTs['S']
# Multiplying a CPT should yield a Factor
result = S_I.mul(I).div(I)
self.assertIsInstance(result, Factor)
self.assertTrue(np.allclose(result.values, S_I.values))
def test_node_cpt(self):
"""Test getting/setting node's CPT."""
node = self.Gs['I']
cpts = examples.get_student_CPTs()
with self.assertRaises(Exception):
node.cpt = 1
with self.assertRaises(Exception):
node.cpt = CPT(cpts['G'].as_factor(), conditioned=['I', 'D'])
with self.assertRaises(Exception):
node.cpt = CPT(cpts['G'])
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_repr(self):
"""Test repr(jpt)."""
CPTs = examples.get_student_CPTs()
I = CPTs['I']
S_I = CPTs['S']
self.assertEqual(I.display_name, 'P(I)')
self.assertEqual(S_I.display_name, 'P(S|I)')
# Unfortunately, pandas.DataFrame._repr_html_() returns syntactically
# invalid html, so we cannot validate the html itself :-(.
try:
html = S_I._repr_html_()
except Exception as e:
self.fail('Creating an HTML representation raised an exception?')
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_as_factor(self):
"""Test CPT.as_factor()."""
CPTs = examples.get_student_CPTs()
G_ID = CPTs['G']
self.assertIsInstance(G_ID.as_factor(), Factor)