FFT算法FFT、IFFT、功率谱计算，包括汉风…

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FFT算法进行ＦＦＴ　、ＩＦＦＴ、功率谱计算，包括Hamming 窗、Hanning 窗、triangle 窗、Blackman 窗、4 term Blackman-Harris 窗几种窗函数的功率谱计算功能。-FFT algorithms FFT, IFFT, power spectrum calculation, including the Hamming window, Hanning window, triangle window, Blackman window, 4 term Blackman-Harris window of several of the power spectrum window function computing power.