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doc: add function descriptions to Signal_prep funcs

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Skudalen 2021-06-24 13:30:32 +02:00
parent fecf1aaae2
commit 3834141121
1 changed files with 11 additions and 5 deletions
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16
Signal_prep.py
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@ -104,11 +104,12 @@ def prep_df(df:DataFrame):
y = df.iloc[:,1].to_numpy() y = df.iloc[:,1].to_numpy()
return y, duration return y, duration
# Normalizes a ndarray of a signal to the scale of int16(32767)
def normalize_wave(y_values): def normalize_wave(y_values):
y = np.int16((y_values / y_values.max()) * 32767) y = np.int16((y_values / y_values.max()) * 32767)
return y return y
# Takes the FFT of a DataFrame object
def fft_of_df(df:DataFrame): def fft_of_df(df:DataFrame):
y_values, duration = prep_df(df) y_values, duration = prep_df(df)
N = y_values.size N = y_values.size
@ -117,20 +118,25 @@ def fft_of_df(df:DataFrame):
y_f = fft(norm) y_f = fft(norm)
return x_f, y_f, duration return x_f, y_f, duration
# Removes noise with db4 wavelet function
def denoise_signal_pywt(df:DataFrame): def denoise_signal_pywt(df:DataFrame):
y_values, duration = prep_df(df) y_values, duration = prep_df(df)
norm = normalize_wave(y_values) #y_values = normalize_wave(y_values)
wavelet = pywt.Wavelet('db4') wavelet = pywt.Wavelet('db4')
cA, cD = pywt.dwt(norm, wavelet) cA, cD = pywt.dwt(y_values, wavelet)
x = np.array(range(int(np.floor((y_values.size + wavelet.dec_len - 1) / 2)))) x = np.array(range(int(np.floor((y_values.size + wavelet.dec_len - 1) / 2))))
print(x) print(x)
return x, cA return x, cA
# Plots DataFrame objects
def plot_df(df:DataFrame): def plot_df(df:DataFrame):
lines = df.plot.line(x='timestamp') lines = df.plot.line(x='timestamp')
plt.show() plt.show()
def plot_transformed(x_f, y_f): # Plots ndarrays after transformations
def plot_trans(x_f, y_f):
plt.plot(x_f, np.abs(y_f)) plt.plot(x_f, np.abs(y_f))
plt.show() plt.show()
@ -141,5 +147,5 @@ df = handler.get_time_emg_table(file, 1)
#plot_df(df) #plot_df(df)
x_f, y_f = denoise_signal_pywt(df) x_f, y_f = denoise_signal_pywt(df)
#print(trans_df.info) #print(trans_df.info)
plot_transformed(x_f, y_f) plot_trans(x_f, y_f)
#''' #'''