Exemplo n.º 1
0
def test_io(tmpdir, nmm_example):
    alphabet = nmm_example["alphabet"]
    hmm = nmm_example["hmm"]
    dp = nmm_example["dp"]
    dp_task = DPTask.create(dp)

    seq = Sequence.create(b"AUGAUU", alphabet)
    dp_task.setup(seq)
    r = dp.viterbi(dp_task)
    assert_allclose(hmm.loglikelihood(r.sequence, r.path), -7.069201008427531)

    filepath = Path(tmpdir / "prof.nmm")
    with Output.create(bytes(filepath)) as output:
        prof = Profile.create(alphabet)
        prof.append_model(Model.create(hmm, dp))
        output.write(prof)
        output.write(prof)
        output.write(prof)

    with Input.create(bytes(filepath)) as input:
        nmodels = 0
        for prof in input:
            alphabet = prof.alphabet
            model = prof.models[0]
            dp_task = DPTask.create(model.dp)
            seq = Sequence.create(b"AUGAUU", alphabet)
            dp_task.setup(seq)
            r = model.dp.viterbi(dp_task)
            hmm = model.hmm
            score = hmm.loglikelihood(r.sequence, r.path)
            assert_allclose(score, -7.069201008427531)
            nmodels += 1
        assert nmodels == 3
Exemplo n.º 2
0
def test_codon_state():
    base = BaseAlphabet.create(b"ACGU", b"X")
    codonp = CodonLprob.create(base)
    codonp.set_lprob(Codon.create(b"AUG", base), log(0.8))
    codonp.set_lprob(Codon.create(b"AUU", base), log(0.1))
    state = CodonState.create(b"M1", codonp)
    assert state.name == b"M1"
    assert_allclose(state.lprob(Sequence.create(b"AUG", base)), log(0.8))
    assert_allclose(state.lprob(Sequence.create(b"AUU", base)), log(0.1))
    assert_allclose(state.lprob(Sequence.create(b"ACU", base)), -inf)
def test_sequence_table():
    alphabet = Alphabet.create(b"ACGT", b"X")
    seqt = SequenceTable.create(alphabet)

    with pytest.raises(RuntimeError):
        seqt.normalize()

    seqt.add(Sequence.create(b"AGTG", alphabet), log(0.2))
    seqt.add(Sequence.create(b"T", alphabet), log(1.2))

    assert_allclose(seqt.lprob(Sequence.create(b"AGTG", alphabet)), log(0.2))
    assert_allclose(seqt.lprob(Sequence.create(b"T", alphabet)), log(1.2))
    assert lprob_is_zero(seqt.lprob(Sequence.create(b"", alphabet)))

    with pytest.raises(RuntimeError):
        seqt.lprob(Sequence.create(b"AT", Alphabet.create(b"AT", b"X")))

    with pytest.raises(RuntimeError):
        seqt.add(Sequence.create(b"AT", Alphabet.create(b"AT", b"X")), log(0.2))

    seqt.normalize()

    assert_allclose(seqt.lprob(Sequence.create(b"AGTG", alphabet)), log(0.2 / 1.4))
    assert_allclose(
        seqt.lprob(Sequence.create(b"T", alphabet)), log(1.2 / 1.4), rtol=1e-6
    )
Exemplo n.º 4
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def test_mute_state():
    alphabet = Alphabet.create(b"ACGU", b"X")
    state = MuteState.create(b"S", alphabet)

    assert state.name == b"S"
    assert_allclose(state.lprob(Sequence.create(b"", alphabet)), log(1.0))
    assert lprob_is_zero(state.lprob(Sequence.create(b"AC", alphabet)))
    assert state.min_seq == 0
    assert state.max_seq == 0
    assert str(state) == "S"
    assert repr(state) == "<MuteState:S>"
Exemplo n.º 5
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def test_table_state():
    alphabet = Alphabet.create(b"ACGU", b"X")
    seqt = SequenceTable.create(alphabet)
    seqt.add(Sequence.create(b"AUG", alphabet), log(0.8))
    seqt.add(Sequence.create(b"AUU", alphabet), log(0.4))

    state = TableState.create(b"M2", seqt)
    assert state.name == b"M2"
    assert_allclose(state.lprob(Sequence.create(b"AUG", alphabet)), log(0.8))
    assert_allclose(state.lprob(Sequence.create(b"AUU", alphabet)), log(0.4))
    assert str(state) == "M2"
    assert repr(state) == "<TableState:M2>"
Exemplo n.º 6
0
def test_io(tmpdir, imm_example):
    alphabet = imm_example["alphabet"]
    hmm = imm_example["hmm"]
    dp = imm_example["dp"]

    dp_task = DPTask.create(dp)
    dp_task.setup(Sequence.create(b"AC", alphabet))
    r = dp.viterbi(dp_task)
    assert_allclose(hmm.loglikelihood(r.sequence, r.path), log(0.48))

    filepath = Path(tmpdir / "tmp.imm")
    with Output.create(bytes(filepath)) as output:
        prof = Profile.create(alphabet)
        prof.append_model(Model.create(hmm, dp))
        output.write(prof)

        prof = Profile.create(alphabet)
        prof.append_model(Model.create(hmm, dp))
        output.write(prof)

        prof = Profile.create(alphabet)
        prof.append_model(Model.create(hmm, dp))
        output.write(prof)

    input = Input.create(bytes(filepath))
    nmodels = 0
    for prof in input:
        model = prof.models[0]
        dp_task = DPTask.create(model.dp)
        dp_task.setup(Sequence.create(b"AC", model.hmm.alphabet))
        r = model.dp.viterbi(dp_task)
        hmm = model.hmm
        assert_allclose(hmm.loglikelihood(r.sequence, r.path), log(0.48))
        nmodels += 1
    input.close()
    assert nmodels == 3

    with Input.create(bytes(filepath)) as input:
        nmodels = 0
        for prof in input:
            model = prof.models[0]
            dp_task = DPTask.create(model.dp)
            dp_task.setup(Sequence.create(b"AC", model.hmm.alphabet))
            r = model.dp.viterbi(dp_task)
            hmm = model.hmm
            assert_allclose(hmm.loglikelihood(r.sequence, r.path), log(0.48))
            nmodels += 1
        assert nmodels == 3
Exemplo n.º 7
0
def test_fragment():
    alphabet = BaseAlphabet.create(b"ACGT", b"X")
    seq = Sequence.create(b"ACAAAGATX", alphabet)

    S = MuteState.create(b"S", alphabet)
    E = MuteState.create(b"E", alphabet)
    M1 = NormalState.create(
        b"M1",
        alphabet,
        [log(0.8), log(0.2), log(0.01),
         log(0.01)],
    )
    M2 = NormalState.create(
        b"M2", alphabet,
        [log(0.4), log(0.6), log(0.1), log(0.6)])

    path = Path.create([
        Step.create(S, 0),
        Step.create(M1, 1),
        Step.create(M2, 1),
        Step.create(E, 0)
    ])

    fragment = Fragment(seq, path)
    i = iter(fragment)

    frag_step = next(i)
    assert bytes(frag_step.sequence) == b""
    assert frag_step.step.seq_len == 0
    assert frag_step.step.state.name == S.name

    frag_step = next(i)
    assert bytes(frag_step.sequence) == b"A"
    assert frag_step.step.seq_len == 1
    assert frag_step.step.state.name == M1.name
Exemplo n.º 8
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def test_hmm():
    abc = BaseAlphabet.create(b"ACGU", b"X")
    baset = BaseLprob.create(abc, (log(0.25), log(0.25), log(0.25), log(0.25)))

    codonp = CodonLprob.create(abc)
    codonp.set_lprob(Codon.create(b"AUG", abc), log(0.8))
    codonp.set_lprob(Codon.create(b"AUU", abc), log(0.1))

    B = MuteState.create(b"B", abc)
    M1 = FrameState.create(b"M1", baset, CodonMarg.create(codonp), 0.02)
    M2 = FrameState.create(b"M2", baset, CodonMarg.create(codonp), 0.01)
    E = MuteState.create(b"E", abc)

    hmm = HMM.create(abc)
    hmm.add_state(B, log(0.5))
    hmm.add_state(M1)
    hmm.add_state(M2)
    hmm.add_state(E)

    hmm.set_transition(B, M1, log(0.8))
    hmm.set_transition(B, M2, log(0.2))
    hmm.set_transition(M1, M2, log(0.1))
    hmm.set_transition(M1, E, log(0.4))
    hmm.set_transition(M2, E, log(0.3))

    dp = hmm.create_dp(E)
    task = DPTask.create(dp)
    task.setup(Sequence.create(b"AUGAUU", abc))
    result = dp.viterbi(task)
    loglik = hmm.loglikelihood(task.sequence, result.path)
    assert_allclose(loglik, -7.069201008427531)
Exemplo n.º 9
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def test_hmm_states():
    alphabet = Alphabet.create(b"ACGU", b"X")
    hmm = HMM.create(alphabet)

    S = MuteState.create(b"S", alphabet)
    hmm.add_state(S)

    seqt = SequenceTable.create(alphabet)
    seqt.add(Sequence.create(b"AGU", alphabet), log(0.8))
    seqt.add(Sequence.create(b"AGG", alphabet), log(0.2))

    M = TableState.create(b"M", seqt)
    hmm.add_state(M)

    with pytest.raises(ValueError):
        hmm.add_state(S)

    with pytest.raises(ValueError):
        hmm.add_state(M)

    assert len(hmm.states()) == 2
Exemplo n.º 10
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def test_hmm_viterbi_2():
    alphabet = Alphabet.create(b"AC", b"X")
    hmm = HMM.create(alphabet)

    S = MuteState.create(b"S", alphabet)
    hmm.add_state(S, log(1.0))

    E = MuteState.create(b"E", alphabet)
    hmm.add_state(E, lprob_zero())

    M1 = NormalState.create(b"M1", alphabet, [log(0.8), log(0.2)])
    hmm.add_state(M1, lprob_zero())

    M2 = NormalState.create(b"M2", alphabet, [log(0.4), log(0.6)])
    hmm.add_state(M2, lprob_zero())

    hmm.set_transition(S, M1, log(1.0))
    hmm.set_transition(M1, M2, log(1.0))
    hmm.set_transition(M2, E, log(1.0))
    hmm.set_transition(E, E, log(1.0))
    hmm.normalize()
    hmm.set_transition(E, E, lprob_zero())

    dp = hmm.create_dp(E)
    dp_task = DPTask.create(dp)

    seq = Sequence.create(b"AC", alphabet)
    dp_task.setup(seq)
    r = dp.viterbi(dp_task)
    assert_allclose(hmm.loglikelihood(seq, r.path), log(0.48))

    seq = Sequence.create(b"AA", alphabet)
    dp_task.setup(seq)
    r = dp.viterbi(dp_task)
    assert_allclose(hmm.loglikelihood(seq, r.path), log(0.32))

    seq = Sequence.create(b"CA", alphabet)
    dp_task.setup(seq)
    r = dp.viterbi(dp_task)
    assert_allclose(hmm.loglikelihood(seq, r.path), log(0.08))

    seq = Sequence.create(b"CC", alphabet)
    dp_task.setup(seq)
    r = dp.viterbi(dp_task)
    assert_allclose(hmm.loglikelihood(seq, r.path), log(0.12))

    hmm.set_transition(M1, E, log(1.0))

    seq = Sequence.create(b"AC", alphabet)
    dp = hmm.create_dp(E)
    dp_task = DPTask.create(dp)
    dp_task.setup(seq)
    r = dp.viterbi(dp_task)
    assert_allclose(hmm.loglikelihood(seq, r.path), log(0.48))

    seq = Sequence.create(b"AA", alphabet)
    dp_task.setup(seq)
    r = dp.viterbi(dp_task)
    assert_allclose(hmm.loglikelihood(seq, r.path), log(0.32))
Exemplo n.º 11
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def test_sequence():
    alphabet = Alphabet.create(b"ACGT", b"X")
    seq = Sequence.create(b"ACAAAGATX", alphabet)

    assert len(seq) == 9
    assert bytes(seq) == b"ACAAAGATX"

    assert str(seq) == "ACAAAGATX"
    assert repr(seq) == "<Sequence:ACAAAGATX>"

    Sequence.create(b"ACGXXT", alphabet)

    with pytest.raises(RuntimeError):
        Sequence.create(b"ACGWT", alphabet)

    with pytest.raises(RuntimeError):
        Sequence.create("ACGTç".encode(), alphabet)
Exemplo n.º 12
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def test_hmm_viterbi_1():
    alphabet = Alphabet.create(b"ACGU", b"X")
    hmm = HMM.create(alphabet)

    S = MuteState.create(b"S", alphabet)
    hmm.add_state(S, log(1.0))

    E = MuteState.create(b"E", alphabet)
    hmm.add_state(E, lprob_zero())

    M1 = NormalState.create(
        b"M1",
        alphabet,
        [log(0.8), log(0.2), lprob_zero(), lprob_zero()],
    )
    hmm.add_state(M1, lprob_zero())

    M2 = NormalState.create(
        b"M2",
        alphabet,
        [log(0.4 / 1.6), log(0.6 / 1.6), lprob_zero(), log(0.6 / 1.6)],
    )
    hmm.add_state(M2, lprob_zero())

    hmm.set_transition(S, M1, log(1.0))
    hmm.set_transition(M1, M2, log(1.0))
    hmm.set_transition(M2, E, log(1.0))
    hmm.set_transition(E, E, log(1.0))
    hmm.normalize()

    hmm.set_transition(E, E, lprob_zero())
    assert_allclose(hmm.transition(E, E), lprob_zero())
    assert_allclose(hmm.transition(S, S), lprob_zero())
    assert_allclose(hmm.transition(S, E), lprob_zero())
    assert_allclose(hmm.transition(E, S), lprob_zero())

    dp = hmm.create_dp(E)
    dp_task = DPTask.create(dp)
    seq = Sequence.create(b"AC", alphabet)
    dp_task.setup(seq)
    result = dp.viterbi(dp_task)
    assert_allclose(hmm.loglikelihood(seq, result.path), log(0.3))
Exemplo n.º 13
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def test_normal_state():
    alphabet = Alphabet.create(b"ACGT", b"X")

    state = NormalState.create(
        b"M0",
        alphabet,
        [log(0.1), log(0.2), log(0.3), log(0.3)],
    )
    assert state.name == b"M0"
    assert_allclose(state.lprob(Sequence.create(b"A", alphabet)), log(0.1))
    assert_allclose(state.lprob(Sequence.create(b"C", alphabet)), log(0.2))
    assert_allclose(state.lprob(Sequence.create(b"G", alphabet)), log(0.3))
    assert_allclose(state.lprob(Sequence.create(b"T", alphabet)), log(0.3))
    assert state.min_seq == 1
    assert state.max_seq == 1

    with pytest.raises(RuntimeError):
        state.lprob(Sequence.create(b"T", Alphabet.create(b"ACGT", b"X")))

    assert lprob_is_zero(state.lprob(Sequence.create(b"AC", alphabet)))

    assert str(state) == "M0"
    assert repr(state) == "<NormalState:M0>"
Exemplo n.º 14
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def test_hmm_loglikelihood():
    alphabet = Alphabet.create(b"ACGU", b"X")
    hmm = HMM.create(alphabet)

    S = MuteState.create(b"S", alphabet)
    hmm.add_state(S, log(1.0))

    E = MuteState.create(b"E", alphabet)
    hmm.add_state(E, lprob_zero())

    M1 = NormalState.create(
        b"M1",
        alphabet,
        [log(0.8), log(0.2), lprob_zero(), lprob_zero()],
    )
    hmm.add_state(M1, lprob_zero())

    M2 = NormalState.create(
        b"M2", alphabet, [log(0.4 / 1.6), log(0.6 / 1.6), lprob_zero(), log(0.6 / 1.6)]
    )
    hmm.add_state(M2, lprob_zero())

    hmm.set_transition(S, M1, log(1.0))
    hmm.set_transition(M1, M2, log(1.0))
    hmm.set_transition(M2, E, log(1.0))
    hmm.set_transition(E, E, log(1.0))
    hmm.normalize()

    p = hmm.loglikelihood(
        Sequence.create(b"AC", alphabet),
        Path.create(
            [
                Step.create(S, 0),
                Step.create(M1, 1),
                Step.create(M2, 1),
                Step.create(E, 0),
            ]
        ),
    )
    assert_allclose(p, log(0.3))

    p = hmm.loglikelihood(
        Sequence.create(b"AA", alphabet),
        Path.create(
            [
                Step.create(S, 0),
                Step.create(M1, 1),
                Step.create(M2, 1),
                Step.create(E, 0),
            ]
        ),
    )
    assert_allclose(p, log(0.2))

    p = hmm.loglikelihood(
        Sequence.create(b"AG", alphabet),
        Path.create(
            [
                Step.create(S, 0),
                Step.create(M1, 1),
                Step.create(M2, 1),
                Step.create(E, 0),
            ]
        ),
    )
    assert_allclose(p, lprob_zero())

    p = hmm.loglikelihood(
        Sequence.create(b"AU", alphabet),
        Path.create(
            [
                Step.create(S, 0),
                Step.create(M1, 1),
                Step.create(M2, 1),
                Step.create(E, 0),
            ]
        ),
    )
    assert_allclose(p, log(0.3))

    p = hmm.loglikelihood(
        Sequence.create(b"CC", alphabet),
        Path.create(
            [
                Step.create(S, 0),
                Step.create(M1, 1),
                Step.create(M2, 1),
                Step.create(E, 0),
            ]
        ),
    )
    assert_allclose(p, log(0.075))

    p = hmm.loglikelihood(
        Sequence.create(b"CA", alphabet),
        Path.create(
            [
                Step.create(S, 0),
                Step.create(M1, 1),
                Step.create(M2, 1),
                Step.create(E, 0),
            ]
        ),
    )
    assert_allclose(p, log(0.05))

    p = hmm.loglikelihood(
        Sequence.create(b"CG", alphabet),
        Path.create(
            [
                Step.create(S, 0),
                Step.create(M1, 1),
                Step.create(M2, 1),
                Step.create(E, 0),
            ]
        ),
    )
    assert_allclose(p, lprob_zero())

    p = hmm.loglikelihood(
        Sequence.create(b"CG", alphabet),
        Path.create(
            [
                Step.create(S, 0),
                Step.create(M1, 1),
                Step.create(M2, 1),
                Step.create(E, 0),
            ]
        ),
    )
    assert_allclose(p, lprob_zero())

    p = hmm.loglikelihood(
        Sequence.create(b"CU", alphabet),
        Path.create(
            [
                Step.create(S, 0),
                Step.create(M1, 1),
                Step.create(M2, 1),
                Step.create(E, 0),
            ]
        ),
    )
    assert_allclose(p, log(0.075))

    p = hmm.loglikelihood(
        Sequence.create(b"GC", alphabet),
        Path.create(
            [
                Step.create(S, 0),
                Step.create(M1, 1),
                Step.create(M2, 1),
                Step.create(E, 0),
            ]
        ),
    )
    assert_allclose(p, lprob_zero())

    p = hmm.loglikelihood(
        Sequence.create(b"GA", alphabet),
        Path.create(
            [
                Step.create(S, 0),
                Step.create(M1, 1),
                Step.create(M2, 1),
                Step.create(E, 0),
            ]
        ),
    )
    assert_allclose(p, lprob_zero())

    p = hmm.loglikelihood(
        Sequence.create(b"GG", alphabet),
        Path.create(
            [
                Step.create(S, 0),
                Step.create(M1, 1),
                Step.create(M2, 1),
                Step.create(E, 0),
            ]
        ),
    )
    assert_allclose(p, lprob_zero())

    p = hmm.loglikelihood(
        Sequence.create(b"GU", alphabet),
        Path.create(
            [
                Step.create(S, 0),
                Step.create(M1, 1),
                Step.create(M2, 1),
                Step.create(E, 0),
            ]
        ),
    )
    assert_allclose(p, lprob_zero())

    p = hmm.loglikelihood(
        Sequence.create(b"UC", alphabet),
        Path.create(
            [
                Step.create(S, 0),
                Step.create(M1, 1),
                Step.create(M2, 1),
                Step.create(E, 0),
            ]
        ),
    )
    assert_allclose(p, lprob_zero())

    p = hmm.loglikelihood(
        Sequence.create(b"UA", alphabet),
        Path.create(
            [
                Step.create(S, 0),
                Step.create(M1, 1),
                Step.create(M2, 1),
                Step.create(E, 0),
            ]
        ),
    )
    assert_allclose(p, lprob_zero())

    p = hmm.loglikelihood(
        Sequence.create(b"UG", alphabet),
        Path.create(
            [
                Step.create(S, 0),
                Step.create(M1, 1),
                Step.create(M2, 1),
                Step.create(E, 0),
            ]
        ),
    )
    assert_allclose(p, lprob_zero())

    p = hmm.loglikelihood(
        Sequence.create(b"UU", alphabet),
        Path.create(
            [
                Step.create(S, 0),
                Step.create(M1, 1),
                Step.create(M2, 1),
                Step.create(E, 0),
            ]
        ),
    )
    assert_allclose(p, lprob_zero())

    M3 = NormalState.create(
        b"M2",
        alphabet,
        [log(0.4), log(0.6), lprob_zero(), log(0.6)],
    )

    with pytest.raises(ValueError):
        hmm.loglikelihood(
            Sequence.create(b"UU", alphabet),
            Path.create(
                [
                    Step.create(S, 0),
                    Step.create(M1, 1),
                    Step.create(M3, 1),
                    Step.create(E, 0),
                ]
            ),
        )
Exemplo n.º 15
0
def test_frame_state():
    base = BaseAlphabet.create(b"ACGU", b"X")
    basep = BaseLprob.create(base,
                             (log(0.25), log(0.25), log(0.25), log(0.25)))

    codonp = CodonLprob.create(base)
    codonp.set_lprob(Codon.create(b"AUG", base), log(0.8))
    codonp.set_lprob(Codon.create(b"AUU", base), log(0.1))

    frame_state = FrameState.create(b"M1", basep, CodonMarg.create(codonp),
                                    0.0)

    assert lprob_is_zero(frame_state.lprob(Sequence.create(b"AUA", base)))
    assert_allclose(frame_state.lprob(Sequence.create(b"AUG", base)), log(0.8))
    assert_allclose(frame_state.lprob(Sequence.create(b"AUU", base)), log(0.1))
    assert lprob_is_zero(frame_state.lprob(Sequence.create(b"AU", base)))
    assert lprob_is_zero(frame_state.lprob(Sequence.create(b"A", base)))
    assert lprob_is_zero(frame_state.lprob(Sequence.create(b"AUUA", base)))
    assert lprob_is_zero(frame_state.lprob(Sequence.create(b"AUUAA", base)))

    codonp.normalize()
    frame_state = FrameState.create(b"M1", basep, CodonMarg.create(codonp),
                                    0.1)

    assert_allclose(frame_state.lprob(Sequence.create(b"AUA", base)),
                    -6.905597115665666)
    assert_allclose(frame_state.lprob(Sequence.create(b"AUG", base)),
                    -0.5347732882047062,
                    rtol=1e-6)
    assert_allclose(frame_state.lprob(Sequence.create(b"AUU", base)),
                    -2.5902373304999466,
                    rtol=1e-6)
    assert_allclose(frame_state.lprob(Sequence.create(b"AU", base)),
                    -2.9158434238698336)
    assert_allclose(frame_state.lprob(Sequence.create(b"A", base)),
                    -5.914503505971854)
    assert_allclose(frame_state.lprob(Sequence.create(b"AUUA", base)),
                    -6.881032208841384)
    assert_allclose(frame_state.lprob(Sequence.create(b"AUUAA", base)),
                    -12.08828960987379)
    assert lprob_is_zero(frame_state.lprob(Sequence.create(b"AUUAAA", base)))

    lprob, codon = frame_state.decode(Sequence.create(b"AUA", base))
    assert_allclose(lprob, -7.128586690537968)
    assert codon.symbols == b"AUG"

    lprob, codon = frame_state.decode(Sequence.create(b"AUAG", base))
    assert_allclose(lprob, -4.813151489562624)
    assert codon.symbols == b"AUG"

    lprob, codon = frame_state.decode(Sequence.create(b"A", base))
    assert_allclose(lprob, -6.032286541628237)
    assert codon.symbols == b"AUG"

    lprob, codon = frame_state.decode(Sequence.create(b"UUU", base))
    assert_allclose(lprob, -8.110186062956258)
    assert codon.symbols == b"AUU"
Exemplo n.º 16
0
 def create_sequence(self, sequence: bytes) -> Sequence:
     return Sequence.create(sequence, self.alphabet)
Exemplo n.º 17
0
def test_hmm_viterbi_3():
    alphabet = Alphabet.create(b"AC", b"X")
    hmm = HMM.create(alphabet)

    S = MuteState.create(b"S", alphabet)
    hmm.add_state(S, log(1.0))

    E = MuteState.create(b"E", alphabet)
    hmm.add_state(E, lprob_zero())

    M1 = NormalState.create(b"M1", alphabet, [log(0.8), log(0.2)])
    hmm.add_state(M1, lprob_zero())

    D1 = MuteState.create(b"D1", alphabet)
    hmm.add_state(D1, lprob_zero())

    M2 = NormalState.create(b"M2", alphabet, [log(0.4), log(0.6)])
    hmm.add_state(M2, lprob_zero())

    D2 = MuteState.create(b"D2", alphabet)
    hmm.add_state(D2, lprob_zero())

    hmm.set_transition(S, M1, log(0.8))
    hmm.set_transition(S, D1, log(0.2))

    hmm.set_transition(M1, M2, log(0.8))
    hmm.set_transition(M1, D2, log(0.2))

    hmm.set_transition(D1, D2, log(0.2))
    hmm.set_transition(D1, M2, log(0.8))

    hmm.set_transition(D2, E, log(1.0))
    hmm.set_transition(M2, E, log(1.0))
    hmm.set_transition(E, E, log(1.0))
    hmm.normalize()
    hmm.set_transition(E, E, lprob_zero())

    dp = hmm.create_dp(E)
    dp_task = DPTask.create(dp)
    seq = Sequence.create(b"AC", alphabet)
    dp_task.setup(seq)
    result = dp.viterbi(dp_task)
    score = hmm.loglikelihood(seq, result.path)
    assert bytes(result.sequence) == b"AC"
    path = result.path
    steps = list(path)
    assert steps[0].seq_len == 0
    assert steps[1].seq_len == 1
    assert steps[2].seq_len == 1
    assert steps[3].seq_len == 0

    assert_allclose(score, log(0.3072))

    seq = Sequence.create(b"AA", alphabet)
    dp_task.setup(seq)
    r = dp.viterbi(dp_task)
    assert_allclose(hmm.loglikelihood(seq, r.path), log(0.2048))

    seq = Sequence.create(b"A", alphabet)
    dp_task.setup(seq)
    r = dp.viterbi(dp_task)
    assert_allclose(hmm.loglikelihood(seq, r.path), log(0.128))

    seq = Sequence.create(b"AC", alphabet)
    dp_task.setup(seq)
    r = dp.viterbi(dp_task)
    assert_allclose(hmm.loglikelihood(seq, r.path), log(0.3072))

    dp = hmm.create_dp(M2)
    dp_task = DPTask.create(dp)
    seq = Sequence.create(b"AC", alphabet)
    dp_task.setup(seq)
    r = dp.viterbi(dp_task)
    assert_allclose(hmm.loglikelihood(seq, r.path), log(0.3072))

    hmm.del_state(E)

    dp = hmm.create_dp(M2)
    dp_task = DPTask.create(dp)
    seq = Sequence.create(b"AC", alphabet)
    dp_task.setup(seq)
    result = dp.viterbi(dp_task)
    assert_allclose(hmm.loglikelihood(seq, result.path), log(0.3072))