formating changes

software/transformations/harmonicTransformations.py

@@ -1,11 +1,11 @@
 # transformations applied to the harmonics of a sound
 
 import numpy as np
-from scipy.signal import resample
 from scipy.interpolate import interp1d
 
+
 def harmonicFreqScaling(hfreq, hmag, freqScaling, freqStretching, timbrePreservation, fs):
-	"""
+    """
 	Frequency scaling of the harmonics of a sound
 	hfreq, hmag: frequencies and magnitudes of input harmonics
 	freqScaling: scaling factors, in time-value pairs (value of 1 no scaling)
@@ -14,35 +14,33 @@ def harmonicFreqScaling(hfreq, hmag, freqScaling, freqStretching, timbrePreserva
 	fs: sampling rate of input sound
 	returns yhfreq, yhmag: frequencies and magnitudes of output harmonics
 	"""
-	if (freqScaling.size % 2 != 0):                        # raise exception if array not even length
-		raise ValueError("Frequency scaling array does not have an even size")
-
-	if (freqStretching.size % 2 != 0):                     # raise exception if array not even length
-		raise ValueError("Frequency stretching array does not have an even size")
-
-	L = hfreq.shape[0]                                                   # number of frames
-	nHarms = hfreq.shape[1]                                              # number of harmonics
-	# create interpolation object with the scaling values 
-	freqScalingEnv = np.interp(np.arange(L), L*freqScaling[::2]/freqScaling[-2], freqScaling[1::2]) 
-	# create interpolation object with the stretching values
-	freqStretchingEnv = np.interp(np.arange(L), L*freqStretching[::2]/freqStretching[-2], freqStretching[1::2]) 
-	yhfreq = np.zeros_like(hfreq)                                        # create empty output matrix
-	yhmag = np.zeros_like(hmag)                                          # create empty output matrix
-	for l in range(L):                                                   # go through all frames
-		ind_valid = np.where(hfreq[l,:]!=0)[0]                             # check if there are frequency values
-		if ind_valid.size == 0:                                            # if no values go to next frame
-			continue
-		if (timbrePreservation == 1) & (ind_valid.size > 1):               # create spectral envelope
-			# values of harmonic locations to be considered for interpolation
-			x_vals = np.append(np.append(0, hfreq[l,ind_valid]),fs/2)     
-			# values of harmonic magnitudes to be considered for interpolation 
-			y_vals = np.append(np.append(hmag[l,0], hmag[l,ind_valid]),hmag[l,-1])     
-			specEnvelope = interp1d(x_vals, y_vals, kind = 'linear',bounds_error=False, fill_value=-100)
-		yhfreq[l,ind_valid] = hfreq[l,ind_valid] * freqScalingEnv[l]       # scale frequencies
-		yhfreq[l,ind_valid] = yhfreq[l,ind_valid] * (freqStretchingEnv[l]**ind_valid) # stretch frequencies
-		if (timbrePreservation == 1) & (ind_valid.size > 1):               # if timbre preservation
-			yhmag[l,ind_valid] = specEnvelope(yhfreq[l,ind_valid])           # change amplitudes to maintain timbre
-		else:
-			yhmag[l,ind_valid] = hmag[l,ind_valid]                           # use same amplitudes as input
-	return yhfreq, yhmag
-
+    if (freqScaling.size % 2 != 0):  # raise exception if array not even length
+        raise ValueError("Frequency scaling array does not have an even size")
+
+    if (freqStretching.size % 2 != 0):  # raise exception if array not even length
+        raise ValueError("Frequency stretching array does not have an even size")
+
+    L = hfreq.shape[0]  # number of frames
+    # create interpolation object with the scaling values
+    freqScalingEnv = np.interp(np.arange(L), L * freqScaling[::2] / freqScaling[-2], freqScaling[1::2])
+    # create interpolation object with the stretching values
+    freqStretchingEnv = np.interp(np.arange(L), L * freqStretching[::2] / freqStretching[-2], freqStretching[1::2])
+    yhfreq = np.zeros_like(hfreq)  # create empty output matrix
+    yhmag = np.zeros_like(hmag)  # create empty output matrix
+    for l in range(L):  # go through all frames
+        ind_valid = np.where(hfreq[l, :] != 0)[0]  # check if there are frequency values
+        if ind_valid.size == 0:  # if no values go to next frame
+            continue
+        if (timbrePreservation == 1) & (ind_valid.size > 1):  # create spectral envelope
+            # values of harmonic locations to be considered for interpolation
+            x_vals = np.append(np.append(0, hfreq[l, ind_valid]), fs / 2)
+            # values of harmonic magnitudes to be considered for interpolation
+            y_vals = np.append(np.append(hmag[l, 0], hmag[l, ind_valid]), hmag[l, -1])
+            specEnvelope = interp1d(x_vals, y_vals, kind='linear', bounds_error=False, fill_value=-100)
+        yhfreq[l, ind_valid] = hfreq[l, ind_valid] * freqScalingEnv[l]  # scale frequencies
+        yhfreq[l, ind_valid] = yhfreq[l, ind_valid] * (freqStretchingEnv[l] ** ind_valid)  # stretch frequencies
+        if (timbrePreservation == 1) & (ind_valid.size > 1):  # if timbre preservation
+            yhmag[l, ind_valid] = specEnvelope(yhfreq[l, ind_valid])  # change amplitudes to maintain timbre
+        else:
+            yhmag[l, ind_valid] = hmag[l, ind_valid]  # use same amplitudes as input
+    return yhfreq, yhmag