class NCDarithTestCases(unittest.TestCase):
"""Test compression distance functions.
abydos.distance.NCDarith
"""
arith = Arithmetic(' '.join(NIALL))
cmp = NCDarith()
cmp_probs = NCDarith(arith.get_probs())
def test_ncd_arith_dist(self):
"""Test abydos.distance.NCDarith.dist."""
self.assertEqual(self.cmp.dist('', ''), 0)
self.assertEqual(self.cmp_probs.dist('', ''), 0)
self.assertGreater(self.cmp.dist('a', ''), 0)
self.assertGreater(self.cmp_probs.dist('a', ''), 0)
self.assertGreater(self.cmp.dist('abcdefg', 'fg'), 0)
self.assertAlmostEqual(self.cmp_probs.dist('Niall', 'Neil'),
0.608695652173913)
self.assertAlmostEqual(self.cmp_probs.dist('Neil', 'Niall'),
0.608695652173913)
self.assertAlmostEqual(self.cmp.dist('Niall', 'Neil'), 0.6875)
self.assertAlmostEqual(self.cmp.dist('Neil', 'Niall'), 0.6875)
self.assertAlmostEqual(self.cmp_probs.dist('Njáll', 'Njall'),
0.714285714285714)
self.assertAlmostEqual(self.cmp_probs.dist('Njall', 'Njáll'),
0.714285714285714)
self.assertAlmostEqual(self.cmp.dist('Njáll', 'Njall'), 0.75)
self.assertAlmostEqual(self.cmp.dist('Njall', 'Njáll'), 0.75)
def test_ncd_arith_sim(self):
"""Test abydos.distance.NCDarith.sim."""
self.assertEqual(self.cmp.sim('', ''), 1)
self.assertEqual(self.cmp_probs.sim('', ''), 1)
self.assertLess(self.cmp.sim('a', ''), 1)
self.assertLess(self.cmp_probs.sim('a', ''), 1)
self.assertLess(self.cmp.sim('abcdefg', 'fg'), 1)
self.assertAlmostEqual(self.cmp_probs.sim('Niall', 'Neil'),
0.3913043478260869)
self.assertAlmostEqual(self.cmp_probs.sim('Neil', 'Niall'),
0.3913043478260869)
self.assertAlmostEqual(self.cmp.sim('Niall', 'Neil'), 0.3125)
self.assertAlmostEqual(self.cmp.sim('Neil', 'Niall'), 0.3125)
self.assertAlmostEqual(self.cmp_probs.sim('Njáll', 'Njall'),
0.285714285714285)
self.assertAlmostEqual(self.cmp_probs.sim('Njall', 'Njáll'),
0.285714285714285)
self.assertAlmostEqual(self.cmp.sim('Njáll', 'Njall'), 0.25)
self.assertAlmostEqual(self.cmp.sim('Njall', 'Njáll'), 0.25)
class ArithmeticCoderTestCases(unittest.TestCase):
"""Test abydos.compression.Arithmetic.train & .Arithmetic.encode."""
niall_probs = {
'a': (Fraction(41, 57), Fraction(91, 114)),
' ': (Fraction(25, 114), Fraction(7, 19)),
'c': (Fraction(97, 114), Fraction(50, 57)),
'e': (Fraction(29, 57), Fraction(73, 114)),
"'": (Fraction(56, 57), Fraction(113, 114)),
'g': (Fraction(47, 57), Fraction(97, 114)),
'\x00': (Fraction(113, 114), Fraction(1, 1)),
'i': (Fraction(73, 114), Fraction(41, 57)),
'M': (Fraction(17, 19), Fraction(52, 57)),
'K': (Fraction(37, 38), Fraction(56, 57)),
'j': (Fraction(50, 57), Fraction(17, 19)),
'\xed': (Fraction(91, 114), Fraction(47, 57)),
'l': (Fraction(0, 1), Fraction(25, 114)),
'o': (Fraction(53, 57), Fraction(107, 114)),
'N': (Fraction(7, 19), Fraction(29, 57)),
'\xe9': (Fraction(52, 57), Fraction(35, 38)),
'\xe1': (Fraction(35, 38), Fraction(53, 57)),
'U': (Fraction(109, 114), Fraction(55, 57)),
'O': (Fraction(55, 57), Fraction(37, 38)),
'h': (Fraction(18, 19), Fraction(109, 114)),
'n': (Fraction(107, 114), Fraction(18, 19)),
}
coder = Arithmetic()
def test_arithmetic_train(self):
"""Test abydos.compression.Arithmetic.train."""
self.coder.train('')
self.assertEqual(self.coder.get_probs(), {'\x00': (0, 1)})
self.coder.train(' '.join(NIALL))
self.assertEqual(self.coder.get_probs(), self.niall_probs)
self.coder.train(' '.join(sorted(NIALL)))
self.assertEqual(self.coder.get_probs(), self.niall_probs)
self.coder.train(' '.join(NIALL))
niall_probs_new = self.coder.get_probs()
self.coder.train(' '.join(sorted(NIALL)))
self.assertEqual(niall_probs_new, self.coder.get_probs())
self.coder.train('\x00'.join(NIALL))
self.assertEqual(niall_probs_new, self.coder.get_probs())
# Test wrapper
self.assertEqual(ac_train(' '.join(sorted(NIALL))), self.niall_probs)
def test_arithmetic_encode(self):
"""Test abydos.compression.Arithmetic.encode."""
self.coder.set_probs(self.niall_probs)
self.assertEqual(self.coder.encode(''), (254, 8))
self.assertEqual(self.coder.encode('a'), (3268, 12))
self.assertEqual(self.coder.encode('Niall'), (3911665, 23))
self.assertEqual(self.coder.encode('Ni\x00ll'), (1932751, 22))
self.assertEqual(self.coder.encode('Niel'), (486801, 20))
self.assertEqual(self.coder.encode('Mean'), (243067161, 28))
self.assertEqual(
self.coder.encode('Neil Noígíallach'), (2133315320471368785758, 72)
)
self.assertRaises(KeyError, self.coder.encode, 'NIALL')
self.coder.set_probs({'\x00': (0, 1)})
self.assertEqual(self.coder.encode(''), (1, 1))
# Test wrapper
self.assertEqual(ac_encode('Niall', self.niall_probs), (3911665, 23))
def test_arithmetic_decode(self):
"""Test abydos.compression.Arithmetic.decode."""
self.coder.set_probs(self.niall_probs)
self.assertEqual(self.coder.decode(254, 8), '')
self.assertEqual(self.coder.decode(3268, 12), 'a')
self.assertEqual(self.coder.decode(3911665, 23), 'Niall')
self.assertEqual(self.coder.decode(1932751, 22), 'Ni ll')
self.assertEqual(self.coder.decode(486801, 20), 'Niel')
self.assertEqual(self.coder.decode(243067161, 28), 'Mean')
self.assertEqual(
self.coder.decode(2133315320471368785758, 72), 'Neil Noígíallach'
)
self.coder.set_probs({})
self.assertEqual(self.coder.decode(0, 0), '')
self.coder.set_probs({'\x00': (0, 1)})
self.assertEqual(self.coder.decode(1, 1), '')
# Test wrapper
self.assertEqual(ac_decode(3911665, 23, self.niall_probs), 'Niall')