```
"""
PLEASE READ
To use this script you need to edit HOME to the directory where the .wav file is.
The .wav file can be any monotonic frequency sweep either up or down in frequency but
it must be trimmed at both ends to remove any leading silence. Frequencies below 1kHz are
ignored since virually all cartridges are well behaved below 1kHz.
The info_line should be alpha-numeric with entries separated by " / " only. The script
will save a .png file that is named from the info line, replacing " / " with "_". As
example "this / is / a / test" will create a file named "this_is_a_test.png"
plotstyle =
1 - traditional
2 - dual axis (twinx)
3 - dual plot
VERSION 8C
"""
from scipy import signal
from scipy.io.wavfile import read
from pathlib import Path
import matplotlib.pyplot as plt
import numpy as np
import datetime
import os
import librosa
#edit here to add a HOME directory, etc.
#HOME = '/Users/user/Documents/' #THIS IS NOT NEEDED IF RAN FROM A FILE
_FILE = 'wavefile.wav'
infoline = 'Cart / Load / Record'
roundlvl = 2
plotstyle = 2
plotdataout = 0
ovdylim = 0
ovdylimvalue = [-25,5]
topdb = 20
framelength = 512
hoplength = 128
#end Edit
print('Input File: ' + str(_FILE))
print('Info Line: ' + str(infoline))
def align_yaxis(ax1, ax2):
y_lims = np.array([ax.get_ylim() for ax in [ax1, ax2]])
# force 0 to appear on both axes, comment if don't need
y_lims[:, 0] = y_lims[:, 0].clip(None, 0)
y_lims[:, 1] = y_lims[:, 1].clip(0, None)
# normalize both axes
y_mags = (y_lims[:,1] - y_lims[:,0]).reshape(len(y_lims),1)
y_lims_normalized = y_lims / y_mags
# find combined range
y_new_lims_normalized = np.array([np.min(y_lims_normalized), np.max(y_lims_normalized)])
# denormalize combined range to get new axes
new_lim1, new_lim2 = y_new_lims_normalized * y_mags
ax1.set_ylim(new_lim1)
ax2.set_ylim(new_lim2)
#Needed to steal Matlab's flat top window
def ft_window(n):
w = []
a0 = 0.21557895
a1 = 0.41663158
a2 = 0.277263158
a3 = 0.083578947
a4 = 0.006947368
pi = np.pi
for x in range(0,n):
w.append(a0 - a1*np.cos(2*pi*x/(n-1)) + a2*np.cos(4*pi*x/(n-1)) - a3*np.cos(6*pi*x/(n-1)) + a4*np.cos(8*pi*x/(n-1)))
return w
audio, Fs = librosa.load(_FILE, sr=None)
filelength = audio.shape[0] / Fs
print('Sample Rate: ' + str("{:,}".format(Fs) + 'Hz'))
print(f"Length: {filelength}s")
trimmedaudio, index = librosa.effects.trim(audio, top_db=topdb, frame_length=framelength, hop_length=hoplength)
input_sig = (trimmedaudio* 32767).astype(int) #scale samples and convert to int
print(f"In/Out (s): {index / Fs}")
frequency = []
amplitude = []
frequency2h = []
amplitude2h = []
frequency3h = []
amplitude3h = []
freqout = []
ampout = []
freqout2h = []
ampout2h = []
freqout3h = []
ampout3h = []
F = int(Fs/100)
win = ft_window(F)
#For Fs sampling use small Fs/100 FFT's so frequency is f/100
#All common sampling rates are divisible by 100
#First try, no overlap and flat top window
#Find the minimum and maximum frequencies and flip the data if the sweep
#is going down in frequency.
y = abs(np.fft.rfft(input_sig[0:F]*win))
minf = np.argmax(y)
y = abs(np.fft.rfft(input_sig[len(input_sig)-F:len(input_sig)]*win))
maxf = np.argmax(y)
if maxf < minf:
maxf,minf = minf,maxf
input_sig = np.flipud(input_sig)
for x in range(0,len(input_sig)-F,F):
y = abs(np.fft.rfft(input_sig[x:x+F]*win))
f = np.argmax(y) #use largest bin
if f >=10:
frequency.append(f*100)
amplitude.append(y[f])
if 2*f<F/2-2 and f >= 10:
f2 = np.argmax(y[(2*f)-2:(2*f)+2])
frequency2h.append(f*100)
amplitude2h.append(y[2*f-2+f2])
if 3*f<F/2-2 and f >= 10:
f3 = np.argmax(y[(3*f)-2:(3*f)+2])
frequency3h.append(f*100)
amplitude3h.append(y[3*f-2+f3])
amp = 0
count = 0
x = minf*100
for x in range(minf*100,(maxf+1)*100,100):
for y in range(0,len(frequency)):
if frequency[y] == x:
amp = amp + amplitude[y]
count = count + 1
if count != 0:
freqout.append(x)
ampout.append(20*np.log10(amp/count))
amp = 0
count = 0
amp = 0
count = 0
x = minf*100
for x in range(minf*100,(maxf+1)*100,100):
for y in range(0,len(frequency2h)):
if frequency2h[y] == x:
amp = amp + amplitude2h[y]
count = count + 1
if count != 0:
freqout2h.append(x)
ampout2h.append(20*np.log10(amp/count))
amp = 0
count = 0
amp = 0
count = 0
x = minf*100
for x in range(minf*100,(maxf+1)*100,100):
for y in range(0,len(frequency3h)):
if frequency3h[y] == x:
amp = amp + amplitude3h[y]
count = count + 1
if count != 0:
freqout3h.append(x)
ampout3h.append(20*np.log10(amp/count))
amp = 0
count = 0
b, a = signal.iirfilter(3,.5, btype='lowpass') #filter some noise
ampout = signal.filtfilt(b,a,ampout)
ampout2h = signal.filtfilt(b,a,ampout2h)
ampout3h = signal.filtfilt(b,a,ampout3h)
norm = ampout[0]
ampout = ampout-norm #amplitude is in dB so normalize by subtraction at [0]
ampout2h = ampout2h-norm
ampout3h = ampout3h-norm
deltah = round((max(ampout)), roundlvl)
deltal = abs(round((min(ampout)), roundlvl))
print('Min Freq: ' + str("{:,}".format(minf * 100) + 'Hz'))
print('Max Freq: ' + str("{:,}".format(maxf * 100) + 'Hz'))
print('Min Ampl: ' + str(round((min(ampout)), 4)) + 'dB')
print('Max Ampl: ' + str(round((max(ampout)), 4)) + 'dB')
print('Delta: ' + str(round((max(ampout) - min(ampout)), 4)) + 'dB')
print('Frequency: ' + str(len(freqout)) + ' list elements')
print('Amplitude: ' + str(len(ampout)) + ' list elements')
print('Amplitude 2h: ' + str(len(ampout2h)) + ' list elements')
print('Amplitude 3h: ' + str(len(ampout3h)) + ' list elements')
if plotdataout == 1:
dampout = [*ampout, *[''] * (len(freqout) - len(ampout))]
dampout2h = [*ampout2h, *[''] * (len(freqout) - len(ampout2h))]
dampout3h = [*ampout3h, *[''] * (len(freqout) - len(ampout3h))]
print('\nPlot Data: (freq, ampl, 2h, 3h)\n')
dataout = list(zip(freqout, dampout, dampout2h, dampout3h))
for fo, ao, ao2, ao3 in dataout:
print(fo, ao, ao2, ao3, sep=', ')
plt.rcParams["xtick.minor.visible"] = True
plt.rcParams["ytick.minor.visible"] = True
if plotstyle == 1:
fig, ax1 = plt.subplots(1, 1, figsize=(14,6))
ax1.semilogx(freqout,ampout,color = 'b', label = 'Freq Response')
ax1.semilogx(freqout2h,ampout2h,color = 'g', label = '2nd Harmonic')
ax1.semilogx(freqout3h,ampout3h,color = 'r', label = '3rd Harmonic')
ax1.set_ylabel("Amplitude (dB)")
ax1.set_xlabel("Frequency (Hz)")
ax1.legend(loc=4)
if plotstyle == 2:
fig, ax1 = plt.subplots(1, 1, figsize=(14,6))
ax2 = ax1.twinx()
if max(ampout) <7:
ax1.set_ylim(-25, 7)
if max(ampout) < 4:
ax1.set_ylim(-25,5)
if max(ampout) < 2:
ax1.set_ylim(-29,3)
if max(ampout) < 0.5:
ax1.set_ylim(-30,2)
if ovdylim == 1:
ax1.set_ylim(*ovdylimvalue)
ax1.semilogx(freqout,ampout,color = 'b', label = 'Freq Response')
ax2.semilogx(freqout2h,ampout2h,color = 'g', label = '2nd Harmonic')
ax2.semilogx(freqout3h,ampout3h,color = 'r', label = '3rd Harmonic')
align_yaxis(ax1, ax2)
ax1.set_ylabel("Amplitude (dB)")
ax2.set_ylabel("Distortion (dB)")
ax1.set_xlabel("Frequency (Hz)")
fig.legend(loc=4, bbox_to_anchor=(0.899, 0.11))
if plotstyle == 3:
fig, (ax1, ax2) = plt.subplots(2, 1, sharex=True, figsize=(14,6))
ax2.grid(True, which="major", axis="both", ls="-", color="black")
ax2.grid(True, which="minor", axis="both", ls="-", color="gainsboro")
if max(ampout) <= 1.75 and min(ampout) >= -1.75:
ax1.set_ylim(-2,2)
ax1.semilogx(freqout,ampout,color = 'b', label = 'Freq Response')
ax2.semilogx(freqout2h,ampout2h,color = 'g', label = '2nd Harmonic')
ax2.semilogx(freqout3h,ampout3h,color = 'r', label = '3rd Harmonic')
ax1.set_ylabel("Amplitude (dB)")
ax2.set_ylabel("Distortion (dB)")
ax2.set_xlabel("Frequency (Hz)")
ax1.legend(loc=4)
ax2.legend(loc=4)
ax1.grid(True, which="major", axis="both", ls="-", color="black")
ax1.grid(True, which="minor", axis="both", ls="-", color="gainsboro")
bbox_args = dict(boxstyle="round", color='b', fc='w', ec='b', alpha=1)
arrow_args = dict(arrowstyle="->")
ax1.annotate('+' + str(deltah) + ', ' + u"\u2212" + str(deltal) + ' dB', color='b', \
xy=(1000,0), xycoords='data', \
xytext=(-15, -20), textcoords='offset points', \
ha="left", va="center", \
bbox=bbox_args, \
#arrowprops=arrow_args \
)
ax1.set_xticks([1000,10000])
ax1.set_xticklabels(['1k','10k'])
ax1.set_title(infoline + "\n", fontsize=16)
mod_date = datetime.datetime.fromtimestamp(os.path.getmtime(_FILE))
plt.figtext(.17, .13, infoline + "\n" + _FILE + "\n" + \
mod_date.strftime("%b %d, %Y %H:%M:%S"), fontsize=8)
plt.savefig(infoline.replace(' / ', '_') +'.png', bbox_inches='tight', pad_inches=.75, dpi=96)
plt.show()
print('\nDone!')
```