#data = load_data('chlorine')
#inserted anomaly
#data[1500:2000, 0:4] = 0.7
#data = data[:,:10]
#data = D['data']
## Missout low valued TS
#mask = data.mean(axis=0) > 50
#data = data[:, mask]
#data = load_ts_data('isp_routers', 'full')
# Z score data
data = zscore(data)
#data = zscore_win(data, 250)
# Fix Nans
whereAreNaNs = np.isnan(data)
data[whereAreNaNs] = 0
# old rank adaptation - thresholds
e_high = 0.99
e_low = 0.90
alpha = 0.98
# New rank adaptation - EWMA
F_min = 0.92
epsilon = 0.02
EW_mean_alpha = 0.1 # for incremental mean
def SAX(data, alphabet_size, word_size, minstd=1.0, pre_normed=False):
""" Returns one word for each data stream
word_size == Number of segments data is split into for PAA
alphabet_size == Number of symbols used
"""
num_streams = data.shape[1]
# Need to insert check here for stationary segemnts
mask = data.std(axis=0) < minstd
passed = np.invert(mask)
if np.any(mask):
# Scale data to have a mean of 0 and a standard deviation of 1.
if pre_normed == False:
data[:, passed] = zscore(data[:, passed])
symbol4skips = string.ascii_letters[int(np.ceil(alphabet_size / 2.))]
else:
# Scale data to have a mean of 0 and a standard deviation of 1.
if pre_normed == False:
data = zscore(data)
# Calculate our breakpoint locations.
breakpoints = bp_lookup(alphabet_size)
breakpoints = np.concatenate((breakpoints, np.array([np.Inf])))
# Split the data into a list of word_size pieces.
data = np.array_split(data, word_size, axis=0)
# Predifine Matrices
segment_means = np.zeros((word_size, num_streams))
#segment_symbol = np.zeros((word_size,num_streams), dtype = np.str)
p_array = np.zeros((num_streams, ), dtype=('a1,' * word_size + 'i2'))
p_dict = {}
# Calculate the mean for each section.
for i in range(word_size):
segment_means[i, passed] = data[i][:, passed].mean(axis=0)
# Figure out which break each section is in based on the section_means and
# calculated breakpoints.
for i in range(num_streams):
for j in range(word_size):
if passed[i]:
idx = int(np.where(breakpoints > segment_means[j, i])[0][0])
# Store in phrase_array
p_array[i][j] = string.ascii_letters[idx]
else:
p_array[i][j] = symbol4skips
# Store in phrase_dict
phrase = ''.join(tuple(p_array[i])[:word_size])
if p_dict.has_key(phrase):
p_dict[phrase].append(i)
else:
p_dict[phrase] = [i]
# Put frequency of pattern in p_array
for vals in p_dict.itervalues():
count = len(vals)
for i in range(count):
p_array[vals[i]][-1] = count
return p_array, p_dict, segment_means
#inserted anomaly
data[1500:2000, 10:20] = 0.0
#data = data[:,:20]
#data = D['data']
## Missout low valued TS
#mask = data.mean(axis=0) > 50
#data = data[:, mask]
#data = load_ts_data('isp_routers', 'mid')
# Z score data
data = zscore(data)
#data = zscore_win(data, 250)
# Fix Nans
whereAreNaNs = np.isnan(data)
data[whereAreNaNs] = 0
# old rank adaptation - thresholds
e_high = 0.99
e_low = 0.94
alpha = 0.96
# New rank adaptation - EWMA
F_min = 0.9
epsilon = 0.05
EW_mean_alpha = 0.1 # for incremental mean
def SAX(data, alphabet_size, word_size, minstd = 1.0, pre_normed = False):
""" Returns one word for each data stream
word_size == Number of segments data is split into for PAA
alphabet_size == Number of symbols used
"""
num_streams = data.shape[1]
# Need to insert check here for stationary segemnts
mask = data.std(axis=0) < minstd
passed = np.invert(mask)
if np.any(mask):
# Scale data to have a mean of 0 and a standard deviation of 1.
if pre_normed == False:
data[:,passed] = zscore(data[:, passed])
symbol4skips = string.ascii_letters[int(np.ceil(alphabet_size/2.))]
else:
# Scale data to have a mean of 0 and a standard deviation of 1.
if pre_normed == False:
data = zscore(data)
# Calculate our breakpoint locations.
breakpoints = bp_lookup(alphabet_size)
breakpoints = np.concatenate((breakpoints, np.array([np.Inf])))
# Split the data into a list of word_size pieces.
data = np.array_split(data, word_size, axis=0)
# Predifine Matrices
segment_means = np.zeros((word_size,num_streams))
#segment_symbol = np.zeros((word_size,num_streams), dtype = np.str)
p_array = np.zeros((num_streams,),dtype = ('a1,' * word_size + 'i2'))
p_dict = {}
# Calculate the mean for each section.
for i in range(word_size):
segment_means[i,passed] = data[i][:,passed].mean(axis = 0)
# Figure out which break each section is in based on the section_means and
# calculated breakpoints.
for i in range(num_streams):
for j in range(word_size):
if passed[i]:
idx = int(np.where(breakpoints > segment_means[j,i])[0][0])
# Store in phrase_array
p_array[i][j] = string.ascii_letters[idx]
else:
p_array[i][j] = symbol4skips
# Store in phrase_dict
phrase = ''.join(tuple(p_array[i])[:word_size])
if p_dict.has_key(phrase):
p_dict[phrase].append(i)
else:
p_dict[phrase] = [i]
# Put frequency of pattern in p_array
for vals in p_dict.itervalues():
count = len(vals)
for i in range(count):
p_array[vals[i]][-1] = count
return p_array, p_dict, segment_means
