CurvFit (tm) is a curve fitting program 4 Windows. Lorentzian, Sine, Exponential and Power series are available models to match your data. A Lorentzian series is highly recommended for real data especially for multiple peaked/valleys data. CurvFit is an example of Calculus programming... ie. minutes to solve, days or years to understand solution and what it implies (e.g. wrong model, sampling rate error). See comments in EX*.?
Free download