1. A method of at least one processor, comprising: receiving a query including signal values providing measures of signals between a first wireless device and corresponding access points; ranking the access points for the query based on sorting the signal values; computing, using the ranking, similarity values between the query and respective fingerprints of signal values collected at a plurality of locations in an area, each signal value of the signal values in the fingerprints providing a measure of a signal between at least one wireless device at a location of the plurality of locations and a respective access point of the access points, wherein the computing of the similarity values comprises computing a first signal value difference between the query and a first fingerprint of the fingerprints of signal values, the first signal value difference based on a difference between the signal values of the first fingerprint and a re-ordered collection of the signal values of the first fingerprint, wherein the signal values in the re-ordered collection is according to the ranking of the access points for the query; and determining a location of the first wireless device based on the computed similarity values.