Algorithm 649: A package for computing trigonometric Fourier coefficients based on Lyness's algorithm

We present a package that allows the computation of the trigonometric Fourier coefficients of a smooth function. The function can be provided as a subprogram or as a data list of function values at equally spaced points. The computational cost of the algorithm does not depend on the required number of Fourier coefficients. Numerical results of comparative tests with a standard integrator for oscillatory functions are also reported.