def create(start_spn, end_spn):
"""
Create PitchRange based on start and end scientific pitch notation.
Args:
start_spn: start spn (pitch string).
end_spn: end spn (pitch string).
Returns:
PitchRange based on inputs.
"""
start = DiatonicFoundation.get_chromatic_distance(
DiatonicPitch.parse(start_spn) if isinstance(start_spn, str
) else start_spn)
end = DiatonicFoundation.get_chromatic_distance(
DiatonicPitch.parse(end_spn) if isinstance(end_spn, str
) else end_spn)
return PitchRange(start, end)
def is_pitch_inbounds(self, pitch):
"""
Determines if given chromatic location is in bounds of range.
Args:
pitch: spn text for pitch, e.g. 'c:4' or DiatonticPitch object.
Returns:
boolean indicating if in bounds.
"""
p = DiatonicPitch.parse(pitch) if isinstance(pitch, str) else pitch
return self.is_inbounds(DiatonicFoundation.get_chromatic_distance(p))
def test_semitone_difference(self):
assert DiatonicFoundation.get_chromatic_distance(DiatonicPitch.parse('C:4')) == 48
equi_list = DiatonicFoundation.add_semitones(DiatonicPitch.parse('eb:4'), 13)
assert equi_list is not None
assert len(equi_list) == 3
assert DiatonicPitch.parse('E:5') in equi_list
assert DiatonicPitch.parse('D##:5') in equi_list
assert DiatonicPitch.parse('Fb:5') in equi_list
a = DiatonicPitch.parse('C:5')
b = DiatonicPitch.parse('F#:4')
assert DiatonicFoundation.semitone_difference(a, b) == 6
assert DiatonicFoundation.semitone_difference(b, a) == -6
def _find_closest_pitch(self, pitch):
"""
Given a pitch, find the scale pitch closest to it in chromatic distance.
:param pitch:
:return:
1) closest in half-steps pitch in tonality.
2) chromatic distance measured from closest pitch to given pitch.
Note: algorithm looks for tonal pitches with same letter as pitch first, otherwise nearest non-tonal pitch.
"""
start_octave = max(pitch.octave - 1, ChromaticScale.CHROMATIC_START[0])
end_octave = min(pitch.octave + 1, ChromaticScale.CHROMATIC_END[0])
# Compute the first and last pitches within the start/end octave range. To build a PitchScale
first_pitch = None
for t in self.tonality.annotation:
first_pitch = DiatonicPitch(start_octave, t)
if DiatonicFoundation.get_chromatic_distance(first_pitch) >= ChromaticScale.chromatic_start_index():
break
last_pitch = None
loop_finished = False
for o in range(end_octave, end_octave - 2, -1):
if loop_finished:
break
for t in reversed(self.tonality.annotation):
last_pitch = DiatonicPitch(o, t)
if DiatonicFoundation.get_chromatic_distance(last_pitch) <= ChromaticScale.chromatic_end_index():
loop_finished = True
break
scale = PitchScale(self.tonality, PitchRange.create(first_pitch, last_pitch))
# determine if pitch ltr is in tonality, get that tone
ll = [t for t in self.tones if t.diatonic_letter == pitch.diatonic_tone.diatonic_letter]
if len(ll) == 1:
pp = DiatonicPitch(pitch.octave, ll[0])
return pp, pitch.chromatic_distance - pp.chromatic_distance
# Do something if len(ll) > 1
elif len(ll) > 1:
ll.sort(key=lambda x: abs(x.augmentation_offset - pitch.diatonic_tone.augmentation_offset))
pp = DiatonicPitch(pitch.octave, ll[0])
return pp, pitch.chromatic_distance - pp.chromatic_distance
before_pitch = first_pitch
after_pitch = last_pitch
for p in scale.pitch_scale:
if pitch.chromatic_distance <= p.chromatic_distance:
after_pitch = p
break
else:
before_pitch = p
before_distance = pitch.chromatic_distance - before_pitch.chromatic_distance
after_distance = pitch.chromatic_distance - after_pitch.chromatic_distance
if pitch.diatonic_tone.diatonic_letter == before_pitch.diatonic_tone.diatonic_letter:
closest_distance = before_distance
closest_pitch = before_pitch
elif pitch.diatonic_tone.diatonic_letter == after_pitch.diatonic_tone.diatonic_letter:
closest_distance = after_distance
closest_pitch = after_pitch
else:
if abs(before_distance) < abs(after_distance):
closest_distance = before_distance
closest_pitch = before_pitch
else:
closest_distance = after_distance
closest_pitch = after_pitch
return closest_pitch, closest_distance
