2009/1/5 Neal Becker <ndbeck...@gmail.com>: > I was not aware that chirp-z transform can be used to efficiently compute DFT > over a limited part of the spectrum. I could use this. Any references on > this technique?
The only reference I have is the one mentioned in the source: Rabiner, L.R., R.W. Schafer and C.M. Rader. The Chirp z-Transform Algorithm. IEEE Transactions on Audio and Electroacoustics, AU-17(2):86--92, 1969 The discrete z-transform, X(z_k) = \sum_{n=0}^{N-1} x_n z^{-n} is calculated at M points, z_k = AW^-k, k = 0,1,...,M-1. You can think of the z_k's as a spiral, where A controls the outside radius (starting frequency) and W the rate of inward spiralling. Regards Stéfan _______________________________________________ Numpy-discussion mailing list Numpy-discussion@scipy.org http://projects.scipy.org/mailman/listinfo/numpy-discussion