NInverseFourierCoefficient[expr, n, t] gives a numerical approximation to the function, evaluated at t, whose Fourier exponential series representation has coefficients given by expr, where expr is a function of n.
To use NInverseFourierCoefficient, you first need to load the Fourier Series Package using Needs["FourierSeries`"].
The numerical approximation to the Fourier exponential series representation used by NInverseFourierCoefficient is by default defined to be NSum[expr-2nt, {n, -, }].
Different choices for the definition of the Fourier exponential series representation can be specified using the option FourierParameters.
With the setting FourierParameters->{a, b}, the Fourier exponential series representation used by NInverseFourierCoefficient is .
The parameter b in the setting FourierParameters->{a, b} must be numeric.
In addition to the option FourierParameters, NInverseFourierCoefficient can also accept the options available to NSum. These options are passed directly to NSum.