 Since the inverse DFT is the same as the DFT, but with the opposite sign in the exponent and a 1/"N" factor, any FFT algorithm can easily be adapted for it.The development of fast algorithms for DFT can be traced to Carl Friedrich Gauss's unpublished work in 1805 when he needed it to interpolate the orbit of asteroids Pallas and Juno from sample observations.His method was very similar to the one published in 1965 by James Cooley and John Tukey, who are generally credited for the invention of the modern generic FFT algorithm.