Abstract: A method for determining a value for an integer number of phases using a computerized device, having steps: (a) providing an initial set comprising a plurality of coded integer ambiguity strings; (b) based upon a computed fitness value for each string in the initial set, choosing a selected plurality of integer ambiguity strings; and, (c) using information components from at least a first and second string of this selected plurality, generating a first and second offspring ambiguity string for evaluation. Additional steps: prior to choosing, calculating a probability of selection in connection with each computed fitness value; and generating additional offspring ambiguity strings for which fitness values can be computed. An optimal determination of the value can be used for determination of a position. The method of the invention can be incorporated into a global positioning system (GPS).