73. The method of claim 14 , further comprising determining a similarity score between the comparison vector x and the candidate vector y only if the similarity estimate meets a similarity threshold.
14. The method of claim 13 , further comprising determining a similarity estimate between the comparison vector x and a candidate vector y; if the similarity estimate meets a similarity threshold, determining a similarity score between the comparison vector x and the candidate vector y; and if the similarity score meets the similarity threshold, identifying the pair of vectors (x, y) as a pair of similar vectors.