Python中的 Matplotlib.axes.Axes.magnitude_spectrum()

Matplotlib是Python中的一个库，它是 NumPy 库的数值数学扩展。 Axes 类包含大部分图形元素：Axis、Tick、Line2D、Text、Polygon 等，并设置坐标系。 Axes 的实例通过回调属性支持回调。

matplotlib.axes.Axes.magnitude_spectrum()函数

matplotlib 库的 axes 模块中的Axes.magnitude_spectrum()函数用于绘制幅度谱。

Syntax: Axes.magnitude_spectrum(self, x, Fs=None, Fc=None, window=None, pad_to=None, sides=None, *, data=None, **kwargs)

Parameters: This method accept the following parameters that are described below:

x: This parameter is a sequence of data.
Fs : This parameter is a scalar. Its default value is 2.
window: This parameter take a data segment as an argument and return the windowed version of the segment. Its default value is window_hanning()
sides: This parameter specifies which sides of the spectrum to return. This can have following values : ‘default’, ‘onesided’ and ‘twosided’.
pad_to : This parameter contains the integer value to which the data segment is padded.
Fc: This parameter is also contains the integer value to offsets the x extents of the plot to reflect the frequency range. Its default value is 0

Returns: This returns the following:

spectrum :This returns the angle spectrum in radians.
freqs :This returns the frequencies corresponding to the elements in spectrum.
line : This returns the line created by this function.

The resultant is (spectrum, freqs, line)

编程需要懂一点英语

下面的示例说明了 matplotlib.axes 中的 matplotlib.axes.Axes.magnitude_spectrum()函数：

示例 1：

# Implementation of matplotlib function
import matplotlib.pyplot as plt
import numpy as np
np.random.seed(10**5)
   
dt = 0.0001
Fs = 1 / dt
geeks = np.array([22.00, 61.90, 7.80,
                  24.40, 110.25, 20.05,
                  15.00, 22.80, 34.90,
                  57.30])
  
nse = np.random.randn(len(geeks))
r = np.exp(-geeks / 0.05)
   
s = 0.5 * np.sin(1.5 * np.pi * geeks) + nse
   
# plot magnitude_spectrum
fig, ax = plt.subplots()
ax.magnitude_spectrum(s, Fs = Fs, 
                      color ="green")
  
ax.set_title('matplotlib.axes.Axes.magnitude_spectrum()\
Example')
  
plt.show()

输出：

示例 2：

# Implementation of matplotlib function
import matplotlib.pyplot as plt
import numpy as np
np.random.seed(0)
   
dt = 0.01
Fs = 1 / dt
t = np.arange(0, 10, dt)
res = np.random.randn(len(t))
r = np.exp(-t / 0.05)
   
cres = np.convolve(res, r)*dt
cres = cres[:len(t)]
s = 0.5 * np.sin(1.5 * np.pi * t) + cres
   
# plot simple spectrum
fig, (ax1, ax2) = plt.subplots(2, 1)
ax1.plot(t, s, color ="green")
   
# plot magnitude_spectrum
ax2.magnitude_spectrum(s, Fs = Fs, 
                       color ="green")
   
ax1.set_title('matplotlib.axes.Axes.magnitude_spectrum()\
Example')
  
plt.show()

输出：