python获取信号频率和周期_从FFT中求出信号的周期

我有一个周期信号，我想找出周期。

由于存在边界效应，我首先去掉边界，通过观察第一个和最后一个极小值保持N个周期。在

然后，计算FFT。在

代码：import numpy as np

from matplotlib import pyplot as plt

# The list of a periodic something

L = [2.762, 2.762, 1.508, 2.758, 2.765, 2.765, 2.761, 1.507, 2.757, 2.757, 2.764, 2.764, 1.512, 2.76, 2.766, 2.766, 2.763, 1.51, 2.759, 2.759, 2.765, 2.765, 1.514, 2.761, 2.758, 2.758, 2.764, 1.513, 2.76, 2.76, 2.757, 2.757, 1.508, 2.763, 2.759, 2.759, 2.766, 1.517, 4.012]

# Round because there is a slight variation around actually equals values: 2.762, 2.761 or 1.508, 1.507

L = [round(elt, 1) for elt in L]

minima = min(L)

min_id = L.index(minima)

start = L.index(minima)

stop = L[::-1].index(minima)

L = L[start:len(L)-stop]<