1. A method of analysis of a signal which includes a succession of turning points, comprising the following steps: A. establishing a series of discrete range values for the signal to be analyzed; B. storing information identifying the discrete range value for each successive turning point, in association with a domain value for that turning point, in a turning point memory; C. continuously comparing the penultimate stored turning point range value with the present range value of the input signal; D. upon detection of a range value equality in step C, storing a range pair constituting the ultimate stored turning point range value and the penultimate stored turning point range value, in a range pair memory; E. concurrently with recording of the range pair, in step D, storing a domain pair constituting the domain values associated with the ultimate and penultimate stored turning point range values, in a domain pair memory; F. removing the turning point range values relating to the range pair from subsequent comparison; and G. continuing the foregoing procedure for each turning point and range pair in the input signal.