def create_chordseq(melody, map_file, increase):
'''Creates a variant of the mapped sequence with chords
occurring randomly throughout (chorded sequence). The chords
are of variable length, and are created by taking a base note
and adding other notes from the same section onto it. The chords
appear more frequently as the sequence progresses, similar to the
pauses in a sparse sequence with fading == False.'''
sequence = []
info = Map.from_map_file(map_file)
notes = tools.generate_sequence(melody, info.length)
section_lengths = iter(info.sections)
transition_lengths = iter(info.transitions)
prob = 0.0
for i, letter in enumerate(info.structure):
note_set = info.mapping[letter]
section = tools.generate_section(generator=notes,
length=next(section_lengths),
mapping=info.mapping,
section=letter)
for note in section:
sequence.append(tools.update_chord(note, prob, note_set, increase))
prob += 1 / float(info.length)
try:
next_section = info.structure[i + 1]
note_set = info.mapping[letter] + info.mapping[info.structure[i + 1]]
transition = tools.generate_transition(generator=notes,
length=next(transition_lengths),
mapping=info.mapping,
section=letter,
next_section=next_section)
for note in transition:
sequence.append(tools.update_chord(note, prob, note_set, increase))
prob += 1 / float(info.length)
except IndexError:
pass
return sequence
def test_zero_increase(self):
nvalue = (1,)
nset = [(1,), (2,), (3,), (4,)]
self.assertEqual(tools.update_chord(nvalue, 1, nset, 0), (1,))
def test_note_not_in_set(self):
nvalue = (1,)
nset = [(2,), (3,), (4,)]
self.assertEqual(len(tools.update_chord(nvalue, 1, nset, 2)), 3)
def test_zero_prob(self):
nvalue = (1,)
nset = [(1,), (2,), (3,), (4,)]
self.assertEqual(tools.update_chord(nvalue, 0, nset, 4), (1,))
def test_update(self):
nvalue = (1,)
nset = [(1,), (2,), (3,), (4,)]
self.assertEqual(set(tools.update_chord(nvalue, 1, nset, 4)),
{1, 2, 3, 4})