Smoothing: vectorised + minor changes
continuous-integration/drone/push Build is passing Details

This commit is contained in:
Casper Jansen 2023-02-23 17:33:24 +01:00
parent 5caddec583
commit f5d137b679
1 changed files with 25 additions and 95 deletions

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@ -1,7 +1,7 @@
#!/usr/bin/env python3
# -*- coding: utf-8 -*-
"""
Author: C. Jansen, J.A. de Jong - ASCEE V.O.F.
Author: T. Hekman, J.A. de Jong, C. Jansen - ASCEE V.O.F.
Smooth data in the frequency domain.
@ -174,6 +174,8 @@ def smoothSpectralData(freq, M, sw: SmoothingWidth,
"""
# TODO: Make this function multi-dimensional array aware.
# TODO: This does not work due to complex numbers. Should be split up in
# magnitude and phase.
# Safety
MM = copy.deepcopy(M)
@ -196,8 +198,6 @@ def smoothSpectralData(freq, M, sw: SmoothingWidth,
P = 10**(MM/10) # magnitude [dB] --> power
else:
P = MM # data already given as power
# TODO: This does not work due to complex numbers. Should be split up in
# magnitude and phase.
# elif st == SmoothingType.tf:
# P = P**2
@ -235,85 +235,20 @@ from numpy import arange, log2, log10, pi, ceil, floor, sin
# Integrated Hann window
def intHann(x1, x2):
if (x2 <= -1/2) or (x1 >= 1/2):
return 0
elif x1 <= -1/2:
if x2 >= 1/2:
return 1
else:
return sin(2*pi*x2)/(2*pi) + x2 + 1/2
else:
if x2 >= 1/2:
return 1/2 - sin(2*pi*x1)/(2*pi) - x1
else:
return (sin(2*pi*x2) - sin(2*pi*x1))/(2*pi) + (x2-x1)
def smoothSpectralDataAlt(freq, MdB, sw: SmoothingWidth,
st: SmoothingType = SmoothingType.levels):
"""
According to Tylka_JAES_SmoothingWeights.pdf
"A Generalized Method for Fractional-Octave Smoothing of Transfer Functions
that Preserves Log-Frequency Symmetry"
https://doi.org/10.17743/jaes.2016.0053
par 1.3
eq. 16
Calculate integral of (part of) Hann window.
If the args are vectors, the return value will match those.
Args:
x1: lower bound [-0.5, 0.5]
x2: upper bound [-0.5, 0.5]
Return:
Integral of Hann window between x1 and x2
"""
Noct = 1/sw.value[0]
# M = MdB
M = 10**(MdB/20)
x1 = np.clip(x1, -0.5, 0.5)
x2 = np.clip(x2, -0.5, 0.5)
return (sin(2*pi*x2) - sin(2*pi*x1))/(2*pi) + (x2-x1)
f0 = 0
if freq[0] == 0:
f0 += 1
Nfreq = len(freq) # Number of frequenties
test_smoothed = np.array(M) # Input [Power]
ifreq = freq/(freq[1]-freq[0]) # Frequency, normalized to step=1
ifreq = np.array(ifreq.astype(int))
ifreqMin = ifreq[f0] # Min. freq, normalized to step=1
ifreqMax = ifreq[Nfreq-1] # Max. freq, normalized to step=1
sfact = 2**(Noct/2) # bounds are this factor from the center freq
maxNkp = ifreqMax - floor((ifreqMax-1)/sfact**2)+1
# W = np.zeros(int(np.round(maxNkp)))
kpmin = np.floor(ifreq/sfact).astype(int) # min freq of window
kpmax = np.ceil(ifreq*sfact).astype(int) # max freq of window
for ff in range(f0, len(M)): # loop over input freq
if kpmin[ff] < ifreqMin:
kpmin[ff] = ifreqMin
kpmax[ff] = ceil(ifreq[ff]**2/ifreqMin) # achieved Noct
if np.isclose(kpmin[ff], kpmax[ff]):
kpmax[ff] += 1
NoctAct = log2(kpmax[ff]/kpmin[ff])
elif kpmax[ff] > ifreqMax:
kpmin[ff] = floor(ifreq[ff]**2/ifreqMax) # achieved Noct
kpmax[ff] = ifreqMax
if np.isclose(kpmin[ff], kpmax[ff]):
kpmin[ff] -= 1
NoctAct = log2(kpmax[ff]/kpmin[ff])
else:
NoctAct = Noct # Noct = smoothing width (Noct=6 --> 1/6th octave)
kp = arange(kpmin[ff], kpmax[ff]+1) # freqs of window
Phi1 = log2((kp - 0.5)/ifreq[ff])/NoctAct # integration bounds for hann window
Phi2 = log2((kp + 0.5)/ifreq[ff])/NoctAct
W = np.zeros(len(kp))
for ii in range(len(kp)):
W[ii] = intHann(Phi1[ii], Phi2[ii]) # weight = integration of hann window between Phi1 and Phi2
test_smoothed[ff] = np.dot( M[kpmin[ff]-ifreq[0]:kpmax[ff]-ifreq[0]+1], W[:ii+1] ) # eq 16
test_smoothed = 20*log10(test_smoothed)
return test_smoothed
def smoothCalcMatrixAlt(freq, sw: SmoothingWidth):
@ -336,7 +271,6 @@ def smoothCalcMatrixAlt(freq, sw: SmoothingWidth):
eq. 16
"""
# Settings
tr = 2 # truncate window after 2x std; shorter is faster and less accurate
Noct = sw.value[0]
assert Noct > 0, "'Noct' must be absolute positive"
assert np.isclose(freq[-1]-freq[-2], freq[1]-freq[0]), "Input data must "\
@ -350,7 +284,8 @@ def smoothCalcMatrixAlt(freq, sw: SmoothingWidth):
Q[0, 0] = 1 # in case first point is skipped
x0 = 1 if freq[0] == 0 else 0 # Skip first data point if zero frequency
Noct /= 1.5 # empirical correction factor: window @ -6 dB at Noct bounds
# Noct /= 1.5 # empirical correction factor: window @ -6 dB at Noct bounds
Noct /= 2 # empirical correction factor: window @ -3 dB at Noct bounds
ifreq = freq/(freq[1]-freq[0]) # frequency, normalized to step=1
ifreq = np.array(ifreq.astype(int))
@ -362,7 +297,9 @@ def smoothCalcMatrixAlt(freq, sw: SmoothingWidth):
kpmin = np.floor(ifreq/sfact).astype(int) # min freq of window
kpmax = np.ceil(ifreq*sfact).astype(int) # max freq of window
for ff in range(x0, len(M)): # loop over input freq
# Find window bounds and actual smoothing width
if kpmin[ff] < ifreqMin:
kpmin[ff] = ifreqMin
kpmax[ff] = ceil(ifreq[ff]**2/ifreqMin) # decrease smooth. width
@ -385,9 +322,7 @@ def smoothCalcMatrixAlt(freq, sw: SmoothingWidth):
Phi2 = log2((kp + 0.5)/ifreq[ff]) * NoctAct
# Weights within window = integration of hann window between Phi1, Phi2
W = np.zeros(len(kp))
for ii in range(len(kp)):
W[ii] = intHann(Phi1[ii], Phi2[ii])
W = intHann(Phi1, Phi2)
# Insert W at input freq ii, starting at index 'kpmin[ff]-ifreq[0]'
Q[ff, kpmin[ff]-ifreq[0]:kpmax[ff]-ifreq[0]+1] = W
@ -497,7 +432,7 @@ if __name__ == "__main__":
plt.close('all')
# Initialize
Noct = 3 # Noct = 6 for 1/6 oct. smoothing
Noct = 1 # Noct = 6 for 1/6 oct. smoothing
# # Create dummy data set 1: noise
# fmin = 1e3 # [Hz] min freq
@ -529,40 +464,35 @@ if __name__ == "__main__":
t0 = time.time()
Msm = smoothSpectralData(freq, MdB, sw, st) # current algorithm
t1 = time.time()
MsmAlt = smoothSpectralDataAlt(freq, MdB, sw, st) # alternative algorithm
MsmAlt = smoothSpectralDataAltMatrix(freq, MdB, sw, st) # alternative algorithm, matrix method
t2 = time.time()
MsmAltMatrix = smoothSpectralDataAltMatrix(freq, MdB, sw, st) # alternative algorithm, matrix method
t3 = time.time()
fsm = freq
print(f"Smoothing time: {t1-t0} s")
print(f"Smoothing time: {t2-t1} s (Alt)")
print(f"Smoothing time: {t3-t2} s (Alt Matrix)")
print(f"Smoothing time: {t1-t0} s (Current)")
print(f"Smoothing time: {t2-t1} s (Alternative)")
# Plot - lin frequency
plt.figure()
plt.plot(freq, MdB, '.b')
plt.plot(fsm, Msm, 'r')
plt.plot(fsm, MsmAlt, 'g')
plt.plot(fsm, MsmAltMatrix, '--k')
plt.xlabel('f (Hz)')
plt.ylabel('magnitude')
plt.xlim((0, fmax))
plt.ylim((-90, 1))
plt.grid('both')
plt.title('lin frequency')
plt.legend(['Raw', 'Smooth', 'SmoothAlt', 'SmoothAltMatrix'])
plt.legend(['Raw', 'Smooth', 'SmoothAlt'])
# Plot - log frequency
plt.figure()
plt.semilogx(freq, MdB, '.b')
plt.semilogx(fsm, Msm, 'r')
plt.semilogx(fsm, MsmAlt, 'g')
plt.semilogx(fsm, MsmAltMatrix, '--k')
plt.xlabel('f (Hz)')
plt.ylabel('magnitude')
plt.xlim((100, fmax))
plt.ylim((-90, 1))
plt.grid('both')
plt.title('log frequency')
plt.legend(['Raw', 'Smooth', 'SmoothAlt', 'SmoothAltMatrix'])
plt.legend(['Raw', 'Smooth', 'SmoothAlt'])