comparison Syncopation models/synpy/WNBD.py @ 45:6e9154fc58df

moving the code files to the synpy package directory

+'''
+Author: Chunyang Song
+Institution: Centre for Digital Music, Queen Mary University of London
+
+'''
+from basic_functions import repeat, get_note_indices
+
+# To find the product of multiple numbers
+def cumu_multiply(numbers):
+	product = 1
+	for n in numbers:
+		product = product*n
+	return product
+
+def get_syncopation(bar, parameters = None):
+	syncopation = None
+	
+	noteSequence = bar.get_note_sequence()
+	barTicks = bar.get_bar_ticks()
+	subdivisionSequence = bar.get_subdivision_sequence()
+	strongBeatLevel = bar.get_beat_level()
+	
+	nextbarNoteSequence = None
+	if bar.get_next_bar() != None:
+		nextbarNoteSequence = bar.get_next_bar().get_note_sequence()
+
+	# calculate each strong beat ticks
+	numberOfBeats = cumu_multiply(subdivisionSequence[:strongBeatLevel+1])
+	beatIntervalTicks = barTicks/numberOfBeats
+	# beatsTicks represents the ticks for all the beats in the current bar and the first two beats in the next bar
+	beatsTicks = [i*beatIntervalTicks for i in range(numberOfBeats+2)] 
+	#print beatsTicks
+	totalSyncopation = 0
+	for note in noteSequence:
+	#	print note.to_string()
+		# find such beatIndex such that note.startTime is located between (including) beatsTicks[beatIndex] and (not including) beatsTicks[beatIndex+1]
+		beatIndex = 0
+		while note.startTime < beatsTicks[beatIndex] or note.startTime >= beatsTicks[beatIndex+1]:
+			beatIndex += 1
+
+	#	print beatIndex
+		# calculate the distance of this note to its nearest beat
+		distanceToBeatOnLeft = abs(note.startTime - beatsTicks[beatIndex])/float(beatIntervalTicks)
+		distanceToBeatOnRight = abs(note.startTime - beatsTicks[beatIndex+1])/float(beatIntervalTicks)
+		distanceToNearestBeat = min(distanceToBeatOnLeft,distanceToBeatOnRight)
+	#	print distanceToNearestBeat
+
+		# calculate the WNBD measure for this note, and add to total syncopation value for this bar
+		if distanceToNearestBeat == 0:	
+			totalSyncopation += 0
+		# or if this note is held on past the following beat, but ends on or before the later beat  
+		elif beatsTicks[beatIndex+1] < note.startTime+note.duration <= beatsTicks[beatIndex+2]:
+			totalSyncopation += float(2)/distanceToNearestBeat
+		else:
+			totalSyncopation += float(1)/distanceToNearestBeat
+	#	print totalSyncopation
+
+	return totalSyncopation
+
+#def get_syncopation(seq, subdivision_seq, strong_beat_level, postbar_seq):
+# def get_syncopation(bar, parameters = None):
+# 	syncopation = None
+	
+# 	binarySequence = bar.get_binary_sequence()
+# 	sequenceLength = len(binarySequence)
+# 	subdivisionSequence = bar.get_subdivision_sequence()
+# 	strongBeatLevel = bar.get_beat_level()
+# 	nextbarBinarySequence = None
+
+# 	if bar.get_next_bar() != None:
+# 		nextbarBinarySequence = bar.get_next_bar().get_binary_sequence()
+
+# 	numberOfBeats = cumu_multiply(subdivisionSequence[0:strongBeatLevel+1])	# numberOfBeats is the number of strong beats
+	
+# 	if sequenceLength % numberOfBeats != 0:
+# 		print 'Error: the length of sequence is not subdivable by the subdivision factor in subdivision sequence.'
+# 	else:
+# 		# Find the indices of all the strong-beats
+# 		beatIndices = []
+# 		beatInterval = sequenceLength / numberOfBeats
+# 		for i in range(numberOfBeats+1):
+# 			beatIndices.append(i*beatInterval)
+# 		if nextbarBinarySequence != None:		# if there is a postbar_seq, add another two beats index for later calculation
+# 			beatIndices += [sequenceLength+beatInterval, sequenceLength+ 2* beatInterval]
+
+# 		noteIndices = get_note_indices(binarySequence)	# all the notes
+
+# 		# Calculate the WNBD measure for each note
+# 		def measure_pernote(noteIndices, nextNoteIndex):
+# 			# Find the nearest beats where this note locates - in [beat_indices[j], beat_indices[j+1]) 
+# 			j = 0
+# 			while noteIndices < beatIndices[j] or noteIndices >= beatIndices[j+1]:
+# 				j = j + 1
+			
+# 			# The distance of note to nearest beat normalised by the beat interval
+# 			distanceToNearestBeat = min(abs(noteIndices - beatIndices[j]), abs(noteIndices - beatIndices[j+1]))/float(beatInterval)
+
+# 			# if this note is on-beat
+# 			if distanceToNearestBeat == 0:	
+# 				measure = 0
+# 			# or if this note is held on past the following beat, but ends on or before the later beat  
+# 			elif beatIndices[j+1] < nextNoteIndex <= beatIndices[j+2]:
+# 				measure = float(2)/distanceToNearestBeat
+# 			else:
+# 				measure = float(1)/distanceToNearestBeat
+# 			return measure
+
+# 		total = 0
+# 		for i in range(len(noteIndices)):
+# 			# if this is the last note, end_time is the index of the following note in the next bar
+# 			if i == len(noteIndices)-1:
+# 				# if the next bar is not none or a bar of full rest, 
+# 				# the nextNoteIndex is the sum of sequence length in the current bar and the noteIndex in the next bar
+# 				if nextbarBinarySequence != None and nextbarBinarySequence != repeat([0],len(nextbarBinarySequence)):
+# 					nextNoteIndex = get_note_indices(nextbarBinarySequence)[0]+sequenceLength
+# 				# else when the next bar is none or full rest, end_time is the end of this sequence.
+# 				else:
+# 					nextNoteIndex = sequenceLength
+# 			# else this is not the last note, the nextNoteIndex is the following element in the noteIndices list
+# 			else:
+# 				nextNoteIndex = noteIndices[i+1]
+# 			# sum up the syncopation value for individual note at noteIndices[i]
+# 			total += measure_pernote(noteIndices[i],nextNoteIndex)
+
+# 		#syncopation = float(total) / len(note_indices)
+
+# 	# return the total value, leave the normalisation done in the end
+# 	return total