Remark on stably updating mean and standard deviation of data

Although not published as a numbered algorithm, Hanson's article “Stably Updating Mean and Standard Deviation of Data” in the January, 1975, issue of Communications , [1] describes an algorithm for sequentially recomputing the mean and standard deviation of a weighted series of numbers when new numbers are added to the series. The procedure requires that only a summary matrix of data be retained, not the entire series, for the new mean and standard deviation to be computed.