Constant-step approximation of multi-exponential signals using a least-squares criterion.

A FORTRAN IV computer program is presented which fits up to three exponential terms and a constant to experimental data according to a least-squares criterion. Initial estimates are necessary. but no specific kind of spacing is required. The program was tried out on artificially generated three-exponential curves with added white noise. The parameters required could be determined with satisfactory accuracy. The program uses a considerable amount of CPU time. but can be run on a mini-computer. Exponential Fitting Sum of least squares Stepwise