Harminv is a free program and C library for harmonic inversion: decomposing a time-series into a sum of sinusoids, including exponentially decaying sinusoids. It is based on the "filter diagonalization method" (FDM) of Mandelshtam & Taylor, which maps the harmonic inversion problem onto a small eigen-problem (size proportional to the number of sinusoids). The FDM is often able to obtain much more robust and accurate solutions than alternative methods.
