Question

我试图为我的数据集中的每个轴生成一个频谱图在这里我尝试了什么

dataset = np.loadtxt("trainingdataset.txt", delimiter=",", dtype = np.int32)

fake_size = 1415684
time = np.arange(fake_size)/1415684 # 1kHz
base_freq = 2 * np.pi * 100

x = dataset[:,2]
y = dataset[:,3]
z = dataset[:,4]

xyz_magnitude = x**2 + y**2 + z**2

to_plot = [('x', x), ('y', y), ('z', z), ('xyz', xyz_magnitude)]

for chl, data in to_plot:
    plt.figure(); plt.title(chl)
    d = plt.specgram(data, Fs=1000)
    plt.xlabel('Time [s]'); plt.ylabel('Frequency [Hz]')
    plt.show()

但它会发出以下警告

Warning (from warnings module):
  File "C:\Users\hadeer.elziaat\AppData\Local\Programs\Python\Python36\lib\site-packages\matplotlib\axes\_axes.py", line 7221
    Z = 10. * np.log10(spec)
RuntimeWarning: divide by zero encountered in log10

数据集标题（患者编号，时间/毫秒，x轴，y轴，z轴，标签）

1,15,70,39,-970,0
1,31,70,39,-970,0
1,46,60,49,-960,0
1,62,60,49,-960,0
1,78,50,39,-960,0
1,93,50,39,-960,0
1,109,60,39,-990,0

Answer 1

根据手册，默认缩放比例为dB。如果计算的频谱图中的值为零，则对数刻度的评估将导致错误。

python - 在log10警告中遇到的频谱图除以零

1 个答案: