merge_hairpins

auxjad.mutate.merge_hairpins(selection: abjad.select.Selection) → None

Mutates an input abjad.Selection in place and has no return value; this function merges all consecutive hairpins that share a same trend.

Basic usage:

Merging crescendo hairpins:

>>> staff = abjad.Staff(r"c'4\pp\< d'4 e'4\p\< f'4 g'1\mp")
>>> abjad.show(staff)

>>> abjad.mutate.merge_hairpins(staff[:])
>>> abjad.show(staff)

Merging diminuendo hairpins:

>>> staff = abjad.Staff(r"c'4\ff\> d'4 e'4\mf\> f'4 g'1\pp")
>>> abjad.show(staff)

>>> abjad.mutate.merge_hairpins(staff[:])
>>> abjad.show(staff)

The merge only occurs when hairpins share a trend:

>>> staff = abjad.Staff(r"c'4\pp\< d'4 e'4\p\> f'4 g'1\pp")
>>> abjad.show(staff)

>>> abjad.mutate.merge_hairpins(staff[:])
>>> abjad.show(staff)

Note

Auxjad automatically adds this function as an extension function to abjad.mutate. It can thus be used from either auxjad.mutate or abjad.mutate namespaces. Therefore, the two lines below are equivalent:

>>> auxjad.mutate(staff[:]).merge_hairpins()
>>> abjad.mutate(staff[:]).merge_hairpins()

Gaps:

If there are any gaps between hairpins (i.e. they finish on an earlier leaf than the start of the new hairpin), they will not be merged even if they share a trend.

>>> staff = abjad.Staff(
...     r"c'1\pp\< d'2\f d'2\< e'1\ff f'1\f\> "
...     r"g'2\mp g'2\> a'1\! b'1\ppp"
... )
>>> abjad.show(staff)

>>> auxjad.mutate.merge_hairpins(staff[:])
>>> abjad.show(staff)

Multiple merges:

This function can merge an indefinite number of hairpins:

>>> staff = abjad.Staff(
...     r"c'4\pp\< d'4 e'4\p\< f'4 g'4\mp\< a'4 b'4\mf\< c''4"
...     r"d''4\f\> c''4 b'4\mf\> a'4 g'4\mp\> f'4 e'4\p\> d'4"
...     r"c'1\pp"
... )
>>> abjad.show(staff)

>>> auxjad.mutate.merge_hairpins(staff[:])
>>> abjad.show(staff)