def from_selection(
class_,
selection,
item_class=None,
):
"""
Makes interval segment from component `selection`.
.. container:: example
>>> staff = abjad.Staff("c'8 d'8 e'8 f'8 g'8 a'8 b'8 c''8")
>>> abjad.IntervalSegment.from_selection(
... staff,
... item_class=abjad.NumberedInterval,
... )
IntervalSegment([2, 2, 1, 2, 2, 2, 1])
Returns interval segment.
"""
import abjad
pitch_segment = abjad.PitchSegment.from_selection(selection)
pitches = [_ for _ in pitch_segment]
intervals = (-x for x in mathtools.difference_series(pitches))
return class_(
items=intervals,
item_class=item_class,
)
def _make_timespans(
self,
layer=None,
music_specifiers=None,
target_timespan=None,
timespan_list=None,
):
new_timespans = abjad.TimespanList()
if not self.voice_names and not self.labels:
return new_timespans
rotation_indices = self.rotation_indices or (0,)
rotation_indices = abjad.CyclicTuple(rotation_indices)
context_counter = collections.Counter()
preexisting_timespans = self._collect_preexisting_timespans(
target_timespan=target_timespan,
timespan_list=timespan_list,
)
partitioned_timespans = self._partition_preexisting_timespans(
preexisting_timespans)
for group_index, group in enumerate(partitioned_timespans):
rotation_index = rotation_indices[group_index]
offsets = set()
offsets.add(group.start_offset)
offsets.add(group.stop_offset)
for timespan in group:
if self.include_inner_starts:
offsets.add(timespan.start_offset)
if self.include_inner_stops:
offsets.add(timespan.stop_offset)
offsets = tuple(sorted(offsets))
durations = abjad.Sequence(mathtools.difference_series(offsets))
durations = durations.rotate(rotation_index)
start_offset = offsets[0]
for context_name, music_specifier in music_specifiers.items():
context_seed = context_counter[context_name]
timespans = music_specifier(
durations=durations,
layer=layer,
division_masks=self.division_masks,
padding=self.padding,
seed=context_seed,
start_offset=start_offset,
timespan_specifier=self.timespan_specifier,
voice_name=context_name,
)
context_counter[context_name] += 1
new_timespans.extend(timespans)
return new_timespans
def from_selection(class_, selection, item_class=None):
"""
Initializes interval-class segment from component selection.
.. container:: example
>>> staff_1 = abjad.Staff("c'4 <d' fs' a'>4 b2")
>>> staff_2 = abjad.Staff("c4. r8 g2")
>>> selection = abjad.select((staff_1, staff_2))
>>> abjad.IntervalClassSegment.from_selection(selection)
IntervalClassSegment(['-M2', '-M3', '-m3', '+m7', '+M7', '-P5'])
Returns interval-class segment.
"""
import abjad
pitch_segment = abjad.PitchSegment.from_selection(selection)
pitches = [_ for _ in pitch_segment]
intervals = mathtools.difference_series(pitches)
return class_(items=intervals, item_class=item_class)