setclass/setclass/tests/test_setclass.py

from setclass.setclass import SetClass


# ----------------------------------------------------------------------------
# Functional tests


def test_zero_normalised_pc():
    "Pitch classes are normalised to start at zero"
    a = SetClass(0, 1, 3)
    assert a == SetClass(1, 2, 4)
    assert a == SetClass(4, 5, 7)


def test_modulo_pc():
    "Pitch classes are normalised to modulo tonality (12)"
    a = SetClass(0, 1, 3)
    assert a == SetClass(12, 13, 15)  # modulo down
    assert a == SetClass(-11, -9, -12)  # modulo up


def test_negative_pc():
    "Negative pitch classes are modulo tonality (12)"
    a = SetClass(0, 9, 10)
    assert a == SetClass(-3, -2, 0)


def test_unordered_pc():
    "Set classes are unordered; normalised to incremental sort"
    a = SetClass(0, 1, 3)
    assert a == SetClass(0, 3, 1)
    assert a == SetClass(3, 0, 1)
    assert a == SetClass(1, 3, 0)
    assert a == SetClass(1, 0, 3)
    assert a == SetClass(3, 1, 0)


def test_resolve_duplicate_pc():
    "Set classes are sets, so duplicates (including after modulo) are eliminated"
    a = SetClass(0, 1, 3)
    assert a == SetClass(0, 1, 3, 3, 1)
    assert a == SetClass(0, 12, 1, -11, 15)
    assert a == SetClass(12, 1, -11, 15, -9)


def test_interval_vector():
    "Set classes have an interval vector"
    test = [
        # 2-tuple of set class, expected interval vector
        (SetClass(0, 3, 4, 7, 8, 11), [3, 0, 3, 6, 3, 0]),
        (SetClass(0, 1, 3, 5, 6, 8, 10), [2, 5, 4, 3, 6, 1]),
    ]
    for (sc, iv) in test:
        assert sc.interval_vector == iv


def test_interval_vector_invarant():
    "The interval vector is invariant under inversion and transposition (rotation)"
    test = [
        # 2-tuple of set class, expected interval vector
        (SetClass(0, 3, 4, 7, 8, 11), [3, 0, 3, 6, 3, 0]),
        (SetClass(0, 1, 3, 5, 6, 8, 10), [2, 5, 4, 3, 6, 1]),
    ]
    for (sc, iv) in test:
        for version in (sc.versions + sc.inversion.versions):
            assert version.interval_vector == iv


# ----------------------------------------------------------------------------
# Example Forte 5-20 set class
f520 = SetClass(0, 1, 5, 6, 8)


def test_tonality():
    "Set classes has a default tonality of 12"
    assert f520.tonality == 12


def test_cardinality():
    "Set classes has a set cardinality"
    assert f520.cardinality == 5


def test_brightness():
    "Set classes have a brightness (sum of normalised pitch class values)"
    assert f520.brightness == 20


def test_pitch_classes():
    "Set classes have pitch classes"
    assert len(f520) == 5
    assert len(f520.pitch_classes) == 5


def test_adjacency_intervals():
    "Set classes have a set of adjacency intervals"
    assert len(f520.adjacency_intervals) == 5


def test_versions():
    "Set classes have a set of transpositions (rotations)"
    assert len(f520.versions) == 5


def test_brightest_form():
    b = f520.brightest_form
    assert b in f520.versions
    assert b == SetClass(0, 4, 5, 9, 10)
    assert b.leonard_notation == '[0₄4₁5₄9₁T₂]⁽²⁸⁾'


def test_darkest_form():
    d = f520.darkest_form
    assert d in f520.versions
    assert d == SetClass(0, 1, 3, 7, 8)
    assert d.leonard_notation == '[0₁1₂3₄7₁8₄]⁽¹⁹⁾'


def test_rahn_normal_form():
    r = f520.rahn_normal_form
    assert r in f520.versions
    assert r == SetClass(0, 1, 5, 6, 8)


def test_inversion():
    i = f520.inversion
    assert i not in f520.versions
    assert i not in f520.complement.versions
    assert i not in f520.complement.inversion.versions
    assert i == SetClass(0, 4, 6, 7, 11)


def test_leonard_notation():
    assert f520.leonard_notation == '[0₁1₄5₁6₂8₄]⁽²⁰⁾'


# ----------------------------------------------------------------------------
# Complement of Forte 5-20 set class: Forte 7-20

def test_complement():
    assert f520.complement == SetClass(0, 1, 2, 5, 7, 8, 9)


def test_complement_tonality():
    assert f520.complement.tonality == 12


def test_complement_cardinality():
    assert f520.complement.cardinality == 7


def test_complement_brightness():
    assert f520.complement.brightness == 32


def test_complement_pitch_classes():
    assert len(f520.complement) == 7
    assert len(f520.complement.pitch_classes) == 7


def test_complement_adjacency_intervals():
    assert len(f520.complement.adjacency_intervals) == 7


def test_complement_versions():
    assert len(f520.complement.versions) == 7


def test_complement_rahn_normal_form():
    r = f520.complement.rahn_normal_form
    assert r in f520.complement.versions
    assert r == SetClass(0, 2, 3, 4, 7, 8, 9)


def test_complement_inversion():
    i = f520.complement.inversion
    assert i not in f520.versions
    assert i not in f520.inversion.versions
    assert i not in f520.complement.versions
    assert i == SetClass(0, 3, 4, 5, 7, 10, 11)


def test_complement_brightest_form():
    b = f520.complement.brightest_form
    assert b in f520.complement.versions
    assert b == SetClass(0, 3, 5, 6, 7, 10, 11)
    assert b.leonard_notation == '[0₃3₂5₁6₁7₃T₁E₁]⁽⁴²⁾'


def test_complement_darkest_form():
    d = f520.complement.darkest_form
    assert d in f520.complement.versions
    assert d == SetClass(0, 1, 2, 5, 6, 7, 10)
    assert d.leonard_notation == '[0₁1₁2₃5₁6₁7₃T₂]⁽³¹⁾'


def test_complement_leonard_notation():
    assert f520.complement.leonard_notation == '[0₁1₁2₃5₂7₁8₁9₃]⁽³²⁾'