Hi Nadev, >A long time ago I translated a free code of chirp z transform (zoom fft) >into python.
Thanks, I'll try it out. I did, however read before on the differences: From Numerix http://www.numerix-dsp.com/zoomfft.html: "One common question is : Is the zoom FFT the same as the chirp z-transform. The answer is : Absolutely not. The FFT calculates the FFT at N equally spaced points around the unit circle in the z-plane, the chirp z-transform modifies the locations of these points along a contour that can lie anywhere on the z-plane. In contrast, the zoom-FFT uses digital down conversion techniques to localise the standard FFT to a narrow band of frequencies that are centered on a higher frequency. The chirp z-transform is often used to analyze signals such as speech, that have certain frequency domain charactgeristics. The zoom-FFT is used to reduce the sample rate required when analysing narrowband signals - E.G. in HF communications." http://www-gatago.com/comp/dsp/34830442.html I just saw was good reading too. It will be interesting, and the code is appreciated! Also, czt.c might be particularly fast if compiled with the Intel FFT lib and weave.blitz(). Again, the goal is increased f resolution within a known small band for the ~same CPU cycles... Ray _______________________________________________ Numpy-discussion mailing list Numpy-discussion@scipy.org http://projects.scipy.org/mailman/listinfo/numpy-discussion
