class TestSAX(object): def setUp(self): # All tests will be run with 6 letter words # and 5 letter alphabet self.sax = SAX(6, 5, 1e-6) def test_to_letter_rep(self): arr = [7, 1, 4, 4, 4, 4] (letters, indices) = self.sax.to_letter_rep(arr) assert letters == 'eacccc' def test_long_to_letter_rep(self): long_arr = [ 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 6, 6, 6, 6, 10, 100 ] (letters, indices) = self.sax.to_letter_rep(long_arr) assert letters == 'bbbbce' def test_compare_strings(self): base_string = 'aaabbc' similar_string = 'aabbbc' dissimilar_string = 'ccddbc' similar_score = self.sax.compare_strings(base_string, similar_string) dissimilar_score = self.sax.compare_strings(base_string, dissimilar_string) assert similar_score < dissimilar_score
class TestSAX(object): def setUp(self): # All tests will be run with 6 letter words # and 5 letter alphabet self.sax = SAX(6, 5, 1e-6) def test_to_letter_rep(self): arr = [7, 1, 4, 4, 4, 4] (letters, indices) = self.sax.to_letter_rep(arr) assert letters == 'eacccc' def test_to_letter_rep_missing(self): arr = [7, 1, 4, 4, np.nan, 4] (letters, indices) = self.sax.to_letter_rep(arr) assert letters == 'eacc-c' def test_long_to_letter_rep(self): long_arr = [ 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 6, 6, 6, 6, 10, 100 ] (letters, indices) = self.sax.to_letter_rep(long_arr) assert letters == 'bbbbce' def test_long_to_letter_rep_missing(self): long_arr = [ 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, np.nan, 1, 1, 6, 6, 6, 6, 10, 100 ] (letters, indices) = self.sax.to_letter_rep(long_arr) assert letters == 'bbb-ce' def test_compare_strings(self): base_string = 'aaabbc' similar_string = 'aabbbc' dissimilar_string = 'ccddbc' similar_score = self.sax.compare_strings(base_string, similar_string) dissimilar_score = self.sax.compare_strings(base_string, dissimilar_string) assert similar_score < dissimilar_score def test_compare_strings_missing(self): assert self.sax.compare_strings('a-b-c-', 'b-c-d-') == 0 def test_normalize_missing(self): # two arrays which should normalize to the same result # except one should contain a nan value in place of the input nan value incomplete_arr_res = self.sax.normalize([1, 0, 0, 0, 0, 1, np.nan]) complete_arr_res = self.sax.normalize([1, 0, 0, 0, 0, 1]) assert np.array_equal(incomplete_arr_res[:-1], complete_arr_res) assert np.isnan(incomplete_arr_res[-1]) def test_normalize_under_epsilon(self): array_under_epsilon = self.sax.normalize([1e-7, 2e-7, 1.5e-7]) assert np.array_equal(array_under_epsilon, [0, 0, 0])
class TestSAX(object): def setUp(self): # All tests will be run with 6 letter words # and 5 letter alphabet self.sax = SAX(6, 5, 1e-6) def test_to_letter_rep(self): arr = [7, 1, 4, 4, 4, 4] (letters, indices, letter_boundries) = self.sax.to_letter_rep(arr) assert letters == 'eacccc' def test_long_to_letter_rep(self): long_arr = [ 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 6, 6, 6, 6, 10, 100 ] (letters, indices, letter_boundries) = self.sax.to_letter_rep(long_arr) assert letters == 'bbbbce' def test_compare_strings(self): base_string = 'aaabbc' similar_string = 'aabbbc' dissimilar_string = 'ccddbc' similar_score = self.sax.compare_strings(base_string, similar_string) dissimilar_score = self.sax.compare_strings(base_string, dissimilar_string) assert similar_score < dissimilar_score def test_from_letter_rep(self): arr = [7, 1, 4, 4, 4, 4] (letters, indices, letter_boundries) = self.sax.to_letter_rep(arr) reconstructed = self.sax.from_letter_rep(letters, indices, letter_boundries) assert allclose(reconstructed, [6.21, 1.78, 4.0, 4.0, 4.0, 4.0], atol=0.01) def test_breakpoints(self): assert allclose(self.sax.breakpoints(3), [-0.43, 0.43], atol=0.01) assert allclose(self.sax.breakpoints(2), [0], atol=0.01) assert allclose(self.sax.breakpoints(20), [ -1.64, -1.28, -1.04, -0.84, -0.67, -0.52, -0.39, -0.25, -0.13, 0, 0.13, 0.25, 0.39, 0.52, 0.67, 0.84, 1.04, 1.28, 1.64 ], atol=0.01) def test_interval_centres(self): assert allclose(self.sax.interval_centres(2), [-0.67, 0.67], atol=0.01) assert allclose(self.sax.interval_centres(3), [-0.96, 0.0, 0.96], atol=0.01) assert allclose(self.sax.interval_centres(30), [ -2.12, -1.64, -1.38, -1.19, -1.03, -0.90, -0.78, -0.67, -0.57, -0.47, -0.38, -0.29, -0.21, -0.12, -0.04, 0.04, 0.12, 0.21, 0.29, 0.38, 0.47, 0.57, 0.67, 0.78, 0.90, 1.03, 1.19, 1.38, 1.64, 2.12 ], atol=0.01)
def ComputeSax(sample_data, sample_data2): sample_data = sample_data.as_matrix() sample_data2 = sample_data2.as_matrix() ######################################### # SAX - Symbolic aggregate approximation #http://www.cs.ucr.edu/~eamonn/SAX.pdf ########################################## #PARAMETERS: #W: The number of PAA segments representing the time series - aka the len() # of the string representing the timeseries - useful for dimensionality reduction #Alphabet size: Alphabet size (e.g., for the alphabet = {a,b,c} = 3) downsample_ratio = 200 word_length = len(sample_data[:, 1]) / downsample_ratio alphabet_size = 7 s = SAX(word_length, alphabet_size) mic_distances = [] for mic in range(1, 5): (x1String, x1Indices) = s.to_letter_rep(sample_data[:, mic]) (x2String, x2Indices) = s.to_letter_rep(sample_data2[:, mic]) #print x1String x1x2ComparisonScore = s.compare_strings(x1String, x2String) mic_distances.append(x1x2ComparisonScore) #print "Mic: " + str(mic) + ", distance= " + str(x1x2ComparisonScore) return mic_distances
class TestSAX(object): def setUp(self): # All tests will be run with 6 letter words # and 5 letter alphabet self.sax = SAX(6, 5, 1e-6) def test_to_letter_rep(self): arr = [7,1,4,4,4,4] (letters, indices) = self.sax.to_letter_rep(arr) assert letters == 'eacccc' def test_to_letter_rep_missing(self): arr = [7,1,4,4,np.nan,4] (letters, indices) = self.sax.to_letter_rep(arr) assert letters == 'eacc-c' def test_long_to_letter_rep(self): long_arr = [1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,6,6,6,6,10,100] (letters, indices) = self.sax.to_letter_rep(long_arr) assert letters == 'bbbbce' def test_long_to_letter_rep_missing(self): long_arr = [1,1,1,1,1,1,1,1,1,1,1,1,1,1,np.nan,1,1,6,6,6,6,10,100] (letters, indices) = self.sax.to_letter_rep(long_arr) assert letters == 'bbb-ce' def test_compare_strings(self): base_string = 'aaabbc' similar_string = 'aabbbc' dissimilar_string = 'ccddbc' similar_score = self.sax.compare_strings(base_string, similar_string) dissimilar_score = self.sax.compare_strings(base_string, dissimilar_string) assert similar_score < dissimilar_score def test_compare_strings_missing(self): assert self.sax.compare_strings('a-b-c-', 'b-c-d-') == 0 def test_normalize_missing(self): # two arrays which should normalize to the same result # except one should contain a nan value in place of the input nan value incomplete_arr_res = self.sax.normalize([1,0,0,0,0,1,np.nan]) complete_arr_res = self.sax.normalize([1,0,0,0,0,1]) assert np.array_equal(incomplete_arr_res[:-1], complete_arr_res) assert np.isnan(incomplete_arr_res[-1]) def test_normalize_under_epsilon(self): array_under_epsilon = self.sax.normalize([1e-7, 2e-7, 1.5e-7]) assert np.array_equal(array_under_epsilon, [0,0,0])
class TestSAX(object): def setUp(self): # All tests will be run with 6 letter words # and 5 letter alphabet self.sax = SAX(6, 5, 1e-6) def test_to_letter_rep(self): arr = [7, 1, 4, 4, 4, 4] (letters, indices) = self.sax.to_letter_rep(arr) assert letters == "eacccc" def test_long_to_letter_rep(self): long_arr = [1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 6, 6, 6, 6, 10, 100] (letters, indices) = self.sax.to_letter_rep(long_arr) assert letters == "bbbbce" def test_compare_strings(self): base_string = "aaabbc" similar_string = "aabbbc" dissimilar_string = "ccddbc" similar_score = self.sax.compare_strings(base_string, similar_string) dissimilar_score = self.sax.compare_strings(base_string, dissimilar_string) assert similar_score < dissimilar_score
def min_dist_sax(t1String,t2String,word,alpha,eps=0.000001): s=SAX(word,alpha,eps) return s.compare_strings(t1String,t2String)
def min_dist_sax(t1String, t2String, word, alpha, eps=0.000001): s = SAX(word, alpha, eps) return s.compare_strings(t1String, t2String)