我正在尝试将我的工作二阶巴特沃斯低通滤波器转换为 python 中的一阶,但它给了我非常大的数字。这是我的二阶巴特沃思:
import math
import numpy as np
def bw_2nd(x=100, y, fc=200, fs=1000):
filtered_y = np.zeros(len(x))
omega_c = math.tan(np.pi*fc/fs)
k1 = np.sqrt(2)*omega_c
k2 = omega_c**2
a0 = k2/(1+k1+k2)
a1 = 2*a0
a2 = a0
k3 = 2*a0/k2
b1 = -(-2*a0+k3)
b2 = -(1-2*a0-k3)
filtered_y[0] = y[0]
filtered_y[1] = y[1]
for i in range(2, len(x)):
filtered_y[i] = np.int(a0*y[i]+a1*y[i-1]+a2*y[i-2]-(b1*filtered_y[i-1]+b2*filtered_y[i-2]))
return filtered_y
这是我的非工作一阶巴特沃思:
def bw_1st(x=100, y, fc=200, fs=1000):
filtered_y = np.zeros(len(x))
omega_c = math.tan(np.pi*fc/fs)
k1 = np.sqrt(2)*omega_c
k2 = omega_c**2
a0 = k2/(1+k1+k2)
a1 = 2*a0
a2 = a0
k3 = 2*a0/k2
b1 = -(-2*a0+k3)
filtered_y[0] = y[0]
for i in range(1, len(x)):
filtered_y[i] = np.int(a0*y[i]+a1*y[i-1]-(b1*filtered_y[i-1]))
return filtered_y
...我删除了所有 [i-2],它们是前馈和反馈。我以为它会起作用,但它没有。你能告诉我如何解决这个问题吗?谢谢你。