def perform_promotion(w1_in,w2_in,w1_out,w2_out):
"""
Takes 2 isax sequences and promotes each symbol to the higher cardinality
:return:
"""
for x in xrange(len(w1_in.symbols)):
a = sy.Symbol()
b = sy.Symbol()
sy.perform_promotion(w1_in.symbols[x],w2_in.symbols[x],a,b)
w1_out.symbols.append(a)
w2_out.symbols.append(b)
def sax_distance(self,other):
"""
Calculates SAX euclidean distance between two iSAX sequences.
:param other:
:return:
"""
alphabet = alpha.NormalAlphabet()
sqd_dist = 0
# Compare symbol by symbol
for x in xrange(len(self.symbols)):
a = sy.Symbol()
b = sy.Symbol()
sy.perform_promotion(self.symbols[x],other.symbols[x],a,b)
distance_matrix = np.array([[0],[0]])
distance_matrix = alphabet.get_distance_matrix(a.cardinality)
local_dist = distance_matrix[a.sax_character][b.sax_character]
sqd_dist += local_dist
return sqd_dist
def mind_dist(self,other):
alphabet = alpha.NormalAlphabet()
sqd_dist = 0
for x in xrange(len(self.symbols)):
a = sy.Symbol()
b = sy.Symbol()
sy.perform_promotion(self.symbols[x],other.symbols[x],a,b)
distance_matrix = alphabet.get_distance_matrix(a.cardinality)
local_dist = distance_matrix[a.sax_character][b.sax_character]
sqd_dist += local_dist * local_dist
# get the sq root of the sum of the squares
dist_sqrt = math.sqrt(sqd_dist)
# Calculate the coefficient
original_ts_length = self.orig_length * 1.0
derived_sax_length = len(self.symbols)
coef = math.sqrt(original_ts_length/derived_sax_length)
return dist_sqrt * coef
def test_promote_symbol(self):
A_in = sy.Symbol(0, 2)
B_in = sy.Symbol(1, 2)
A_out = sy.Symbol(0, 0)
B_out = sy.Symbol(0, 0)
sy.perform_promotion(A_in, B_in, A_out, B_out)
self.assertEquals(A_out.cardinality, 2)
self.assertEquals(B_out.cardinality, 2)
self.assertEquals(A_out.sax_character,0)
self.assertEquals(B_out.sax_character,1)
A_in = sy.Symbol(6, 8)
B_in = sy.Symbol(0, 2)
A_out = sy.Symbol(0, 0)
B_out = sy.Symbol(0, 0)
sy.perform_promotion(A_in, B_in, A_out, B_out)
self.assertEquals(B_out.cardinality, 8)
self.assertEquals(A_out.sax_character, 6)
self.assertEquals(B_out.sax_character, 3)
A_in = sy.Symbol(1, 2)
B_in = sy.Symbol(3, 8)
A_out = sy.Symbol(0, 0)
B_out = sy.Symbol(0, 0)
sy.perform_promotion(A_in, B_in, A_out, B_out)
self.assertEquals(A_out.cardinality, 8)
self.assertEquals(B_out.cardinality, 8)
self.assertEquals(A_out.sax_character, 4)
self.assertEquals(B_out.sax_character, 3)
A_in = sy.Symbol(1, 2)
B_in = sy.Symbol(0, 8)
A_out = sy.Symbol(0, 0)
B_out = sy.Symbol(0, 0)
sy.perform_promotion(A_in, B_in, A_out, B_out)
self.assertEquals(A_out.cardinality, 8)
self.assertEquals(B_out.cardinality, 8)
self.assertEquals(A_out.sax_character, 4)
self.assertEquals(B_out.sax_character, 0)
