CurvFit App fits an math equation (series) to one's data; includes interpolation and/or extrapolation.

[Phil]

CurvFit (tm) is a nonlinear curve fitting program. Sine, damped Sine, Lorentz,
Modified Lorentz, Power (ie Polynomial) and Exponential series are presently
available models to match your data. We strongly suggest trying a Lorentz
series for data with multiple peaks or valleys. A calculator exists for
interpolation and/or extrapolation of given data. CurvFit has proven excellent
for hard to fit data. Hard to fit data may take more time -but- it can be done
given the right series and parameter values. For start try curve fitting your
data with a Lorentz series!

A Lorentz function equals 1 / (1 + a x^2). This is a shortened form of the
infinite series inverse (1 + <UTF16-03A3> ai x^2 i). For practical purposes
the shortened Lorentz function is accurate enough. The Lorentz function
equals the derivative of the arc-tangent.

A Modified Lorentz function equals (1 + x) / (1 + a x^2) = (1 + x) * Lorentz
function! Use the modified Lorentz when minimizing number of terms in your
curve fit series. (Someone suggested that the modified Lorentz is a Bessel
function, is it?)

Its Free! Try it, you'll like it! :)

http://fortranCalculus.info/apps/curvfit.html


Phil