23. A system comprising: one or more computers, the one or more computers implementing: a dataset tool to identify a comparison vector x, and a set of candidate vectors corresponding to the vector x; a similarity tool to determine a similarity estimate between the comparison vector x and each candidate vector y in the set of candidate vectors corresponding to x, where the similarity estimate is based on: a sum of a similarity between a set of processed features of the comparison vector x and a set of processed features of the candidate vector y, and a product of a minimum size of at least one of the candidate vector x or a set of non-processed features of the candidate vector y, and a similarity score between a maximum weight of the comparison vector x and a maximum weight of the candidate vector y; and determine a similarity score between the comparison vector x and each candidate vector y for which the similarity estimate meets a similarity threshold; and a results tool to include a new pair of vectors comprising the comparison vector x and the candidate vector y for each candidate vector y in a list of similar pairs of vectors if the similarity score meets the similarity threshold.
23. A system comprising: one or more computers, the one or more computers implementing: a dataset tool to identify a comparison vector x, and a set of candidate vectors corresponding to the vector x; a similarity tool to determine a similarity estimate between the comparison vector x and each candidate vector y in the set of candidate vectors corresponding to x, where the similarity estimate is based on: a sum of a similarity between a set of processed features of the comparison vector x and a set of processed features of the candidate vector y, and a product of a minimum size of at least one of the candidate vector x or a set of non-processed features of the candidate vector y, and a similarity score between a maximum weight of the comparison vector x and a maximum weight of the candidate vector y; and determine a similarity score between the comparison vector x and each candidate vector y for which the similarity estimate meets a similarity threshold; and a results tool to include a new pair of vectors comprising the comparison vector x and the candidate vector y for each candidate vector y in a list of similar pairs of vectors if the similarity score meets the similarity threshold. 24. The system of claim 23 in which the similarity tool determines the similarity estimate of the comparison vector x and the candidate vector y based on a predetermined function such that the similarity estimate is greater than or equal to a similarity score between the comparison vector x and the candidate vector y.