ASCEE/lasp
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Implementation of filter designer

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Anne de Jong 2020-01-18 13:43:22 +01:00
parent 15c8b0d923
commit 1d488c983a
1 changed files with 20 additions and 48 deletions
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68
lasp/filter/soundpressureweighting.py
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@ -136,57 +136,29 @@ class SPLFilterDesigner:
z, p, k = bilinear_zpk(zeros_analog, poles_analog, k_analog, fs)
sos = zpk2sos(z, p, k)
return sos
# return z, p, k
# return zeros_analog, poles_analog, k_analog
def show_Afir():
from asceefig.plot import Figure
def A_Sos_design(self, fs):
"""
Create filter coefficients of the A-weighting filter. Uses the bilinear
transform to convert the analog filter to a digital one.
fs = 48000.
freq_design = np.linspace(0, 17e3, 3000)
freq_design[-1] = fs/2
amp_design = A(freq_design)
amp_design[-1] = 0.
firs = []
Args:
fs: Sampling frequency [Hz]
# firs.append(arbitrary_fir_design(fs,L,freq_design,amp_design,window='hamming'))
# firs.append(arbitrary_fir_design(fs,L,freq_design,amp_design,window='hann'))
firs.append(A_fir_design())
# from scipy.signal import iirdesign
# b,a = iirdesign()
freq_check = np.logspace(0, np.log10(fs/2), 5000)
f = Figure()
Returns:
Sos: Second order sections
"""
# Poles of A-filter
p1 = 2*np.pi*self.f1
p2 = 2*np.pi*self.f2
p3 = 2*np.pi*self.f3
p4 = 2*np.pi*self.f4
f.semilogx(freq_check, 20*np.log10(A(freq_check)))
for fir in firs:
H = freqResponse(fs, freq_check, fir)
f.plot(freq_check, 20*np.log10(np.abs(H)))
zeros_analog = [0,0,0,0]
poles_analog = [p1, p1, p2, p3, p4, p4]
k_analog = p4**2/self._A_uncor(self.fr)
f.fig.get_axes()[0].set_ylim(-75, 3)
def show_Cfir():
from asceefig.plot import Figure
fs = 48000.
freq_design = np.linspace(0, 17e3, 3000)
freq_design[-1] = fs/2
amp_design = C(freq_design)
amp_design[-1] = 0.
firs = []
# firs.append(arbitrary_fir_design(fs,L,freq_design,amp_design,window='hamming'))
# firs.append(arbitrary_fir_design(fs,L,freq_design,amp_design,window='hann'))
firs.append(C_fir_design())
# from scipy.signal import iirdesign
# b,a = iirdesign()
freq_check = np.logspace(0, np.log10(fs/2), 5000)
f = Figure()
f.semilogx(freq_check, 20*np.log10(C(freq_check)))
for fir in firs:
H = freqResponse(fs, freq_check, fir)
f.plot(freq_check, 20*np.log10(np.abs(H)))
f.fig.get_axes()[0].set_ylim(-30, 1)
z, p, k = bilinear_zpk(zeros_analog, poles_analog, k_analog, fs)
sos = zpk2sos(z, p, k)
return sos