1. A computer-based method of clustering data sets comprising executing on a computer the steps of receiving a first set of data containing a plurality of data points, each of which is expressed as a value and an associated error, determining a distance between the first set of data and each of one or more other sets of data, where each of those other data sets contains a plurality of data points, each of which is expressed as a value and an associated error, the determining step including measuring each distance as a function, at least in part, of the error associated with one or more data points in each of the sets of data for which the distance is determined, clustering the first set of data with at least one of the other sets of data, the clustering step including comparing a threshold one or more distances determined in the determining step, generating a composite data set as a function of data points contained in the first set of data and the one or more other sets of data, if any, whose distances compared favorably with the threshold.