def calculate_signature_dissimilarity(self, target_signature):
"""
Calculate the dissimilarity of target_signature the the user's enrolment signatures
:param target_signature: list of the normalized feature vectors of the target signature to compare to this
user's enrolment signatures
:return: dictionary of type
<user enrolment signature id> -> <dissimilarity of target signature to that enrolment signature>
"""
dtw = DTW()
dissimilarities = []
for key, enrolment_signature in self.enrolment_signatures.items():
dissim, matrix = dtw.distance(enrolment_signature,
target_signature, self.WINDOW_SIZE)
dissimilarities.append(dissim)
return np.mean(np.asarray(dissimilarities))
