用于计算待测信号的功率谱密度，方法是通过计算自相关函数的傅立叶变换。-Used to calculate the power spectral density of the test signal, the method by calculating the autocorrelation function of the Fourier transform.

信号处理中的振幅谱和相位谱以及谱密度估计等-1) Calculation of: - One-sided amplitude spectrum - One-sided phase spectrum - Vector of frequencies. 2) The function can plot: - One-sided amplitude spectrum - One-sided phase spectrum. Two examples are g