Hello, the class documentation[1] of fft states "We require the length of data set to be power of 2" and the method documenation[1] this "Perform the base-4 Cooley-Tukey FFT algorithm (including inverse)."
One must be wrong: base-4 alogrithm means that the length of data has to be power of 4 fft without window function is pretty useless, it would be nice to implement typical[2] window functions for example: -Hamming -Hann -Blackman -Trinangle -Rectangle -Welch -Gaussian after having fft and windowfunction, sonogram/spectrogram[3] would be nice and is easy to implement (10 lines of matlab code). for example: public double[][] sonogram (int fftsize, int overlap_factor, int windowfunction) greetings Carsten [1] http://commons.apache.org/math/apidocs/org/apache/commons/math/transform/FastFourierTransformer.html [2] http://en.wikipedia.org/wiki/Window_function [3] http://en.wikipedia.org/wiki/Spectrogram --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
