Python bdd.BDD类代码示例

def test_image_rename_map_checks():
    ordering = {'x': 0, 'xp': 1,
                'y': 2, 'yp': 3,
                'z': 4, 'zp': 5}
    bdd = BDD(ordering)
    # non-adjacent
    rename = {0: 2, 3: 4}
    qvars = set()
    r = _bdd.image(1, 1, rename, qvars, bdd)
    assert r == 1, r
    r = _bdd.preimage(1, 1, rename, qvars, bdd)
    assert r == 1, r
    # overlapping keys and values
    rename = {0: 1, 1: 2}
    with nt.assert_raises(AssertionError):
        _bdd.image(1, 1, rename, qvars, bdd)
    with nt.assert_raises(AssertionError):
        _bdd.preimage(1, 1, rename, qvars, bdd)
    # may be in support after quantification ?
    trans = bdd.add_expr('x -> xp')
    source = bdd.add_expr('x & y')
    qvars = {0}
    rename = {1: 0, 3: 2}
    with nt.assert_raises(AssertionError):
        _bdd.image(trans, source, rename, qvars, bdd)
    # in support of `target` ?
    qvars = set()
    target = bdd.add_expr('y & yp')
    rename = {2: 3}
    with nt.assert_raises(AssertionError):
        _bdd.preimage(trans, target, rename, qvars, bdd)

def test_level_to_variable():
    ordering = {'x': 0, 'y': 1}
    g = BDD(ordering)
    assert g.var_at_level(0) == 'x'
    assert g.var_at_level(1) == 'y'
    with nt.assert_raises(AssertionError):
        g.var_at_level(10)

def test_elimination():
    ordering = {'x': 0, 'y': 1}
    g = BDD(ordering)
    g.roots.add(2)
    # high == low, so node 2 is redundant
    g._succ[2] = (0, 3, 3)
    g._succ[3] = (1, -1, 1)
    h = g.reduction()
    assert set(h) == {1, 2}

def test_isomorphism():
    ordering = {'x': 0}
    g = BDD(ordering)
    g.roots.update([2, 3])
    g._succ[2] = (0, -1, 1)
    g._succ[3] = (0, -1, 1)
    h = g.reduction()
    assert set(h) == {1, 2}, set(h)
    assert 0 not in h
    assert h._succ[1] == (1, None, None)
    assert h._succ[2] == (0, -1, 1)
    assert h.roots == {2}

def test_add_expr():
    ordering = {'x': 0, 'y': 1}
    g = BDD(ordering)
    # x
    ix = ordering['x']
    u = g.add_expr('x')
    h = ref_var(ix)
    compare(u, g, h)
    # x and y
    u = g.add_expr('x && y')
    h = ref_x_and_y()
    compare(u, g, h)

def test_collect_garbage():
    # all nodes are garbage
    g = BDD({'x': 0, 'y': 1})
    u = g.add_expr('x & y')
    n = len(g)
    assert n == 4, n
    uref = g._ref[abs(u)]
    assert uref == 0, uref
    _, v, w = g._succ[abs(u)]
    vref = g._ref[abs(v)]
    wref = g._ref[w]
    assert vref == 5, vref
    assert wref == 1, wref
    g.collect_garbage()
    n = len(g)
    assert n == 1, n
    assert u not in g, g._succ
    assert w not in g, g._succ
    # some nodes not garbage
    # projection of x is garbage
    g = BDD({'x': 0, 'y': 1})
    u = g.add_expr('x & y')
    n = len(g)
    assert n == 4, n
    g._ref[abs(u)] += 1
    uref = g._ref[abs(u)]
    assert uref == 1, uref
    g.collect_garbage()
    n = len(g)
    assert n == 3, n

def x_and_not_y():
    # remember:
    # 2 = !(x & !y)
    # -2 = x & !y
    ordering = {'x': 0, 'y': 1}
    g = BDD(ordering)
    u = 3
    v = -1
    w = 1
    t = (1, v, w)
    g._succ[u] = t
    g._pred[t] = u
    g._ref[abs(v)] += 1
    g._ref[abs(w)] += 1
    g._ref[abs(u)] = 0
    u = 2
    v = 1
    w = 3
    t = (0, v, w)
    g._succ[u] = t
    g._pred[t] = u
    g._ref[abs(v)] += 1
    g._ref[abs(w)] += 1
    g._ref[abs(u)] = 0
    g._min_free = 4
    return g

def test_rename():
    ordering = {'x': 0, 'xp': 1}
    g = BDD(ordering)
    x = g.add_expr('x')
    xp = g.add_expr('xp')
    dvars = {'x': 'xp'}
    xrenamed = _bdd.rename(x, g, dvars)
    assert xrenamed == xp, xrenamed
    ordering = {'x': 0, 'xp': 1,
                'y': 2, 'yp': 3,
                'z': 4, 'zp': 5}
    g = BDD(ordering)
    u = g.add_expr('x && y && ! z')
    dvars = {'x': 'xp', 'y': 'yp', 'z': 'zp'}
    urenamed = _bdd.rename(u, g, dvars)
    up = g.add_expr('xp && yp && ! zp')
    assert urenamed == up, urenamed
    # assertion violations
    # non-neighbors
    dvars = {'x': 'yp'}
    r = _bdd.rename(u, g, dvars)
    r_ = g.add_expr('yp && y && ! z')
    assert r == r_, (r, r_)
    # u not in bdd
    dvars = {'x': 'xp'}
    with nt.assert_raises(AssertionError):
        _bdd.rename(1000, g, dvars)
    # y essential for u
    dvars = {'xp': 'y'}
    with nt.assert_raises(AssertionError):
        _bdd.rename(u, g, dvars)
    # old and new vars intersect
    dvars = {'x': 'x'}
    with nt.assert_raises(AssertionError):
        _bdd.rename(u, g, dvars)

def test_reduce_combined():
    """Fig.5 in 1986 Bryant TOC"""
    ordering = {'x': 0, 'y': 1, 'z': 2}
    g = BDD(ordering)
    g.roots.add(2)
    g._succ[2] = (0, 3, 4)
    g._succ[3] = (1, -1, 5)
    g._succ[4] = (1, 5, 6)
    g._succ[5] = (2, -1, 1)
    g._succ[6] = (2, -1, 1)
    h = g.reduction()
    assert 1 in h
    assert ordering == h.ordering

    r = nx.MultiDiGraph()
    r.add_node(1, level=3)
    r.add_node(2, level=0)
    r.add_node(3, level=1)
    r.add_node(4, level=2)

    r.add_edge(2, 3, value=False, complement=False)
    r.add_edge(2, 4, value=True, complement=False)
    r.add_edge(3, 4, value=True, complement=False)
    r.add_edge(3, 1, value=False, complement=True)
    r.add_edge(4, 1, value=False, complement=True)
    r.add_edge(4, 1, value=True, complement=False)

    (u, ) = h.roots
    compare(u, h, r)

def test_bdd_to_mdd():
    from dd.bdd import BDD

    ordering = {'x': 0, 'y': 1}
    bdd = BDD(ordering)
    u = bdd.add_expr('x & ! y')
    bdd.incref(u)
    # BDD -> MDD
    dvars = dict(
        x=dict(level=1, len=2, bitnames=['x']),
        y=dict(level=0, len=2, bitnames=['y']))
    mdd, umap = dd.mdd.bdd_to_mdd(bdd, dvars)
    # pd = dd.mdd.to_pydot(mdd)
    # pd.write_pdf('mdd.pdf')
    # bdd.dump('bdd.pdf')
    v = umap[abs(u)]
    if u < 0:
        v = -v
    print(v)

def test_dump_load_manager():
    prefix = 'test_dump_load_manager'
    g = BDD({'x': 0, 'y': 1})
    e = 'x & !y'
    u = g.add_expr(e)
    g.incref(u)
    fname = prefix + '.p'
    g._dump_manager(fname)
    h = g._load_manager(fname)
    assert g.assert_consistent()
    u_ = h.add_expr(e)
    assert u == u_, (u, u_)

def test_descendants():
    ordering = dict(x=0, y=1)
    b = BDD(ordering)
    u = b.add_expr('x && y')
    v = b.add_expr('x | y')
    roots = [u, v]
    nodes = b.descendants(roots)
    nodes_u = b.descendants([u])
    nodes_v = b.descendants([v])
    assert u in nodes_u, nodes_u
    assert v in nodes_v, nodes_v
    assert u in nodes, nodes
    assert v in nodes, nodes
    assert 1 in nodes_u, nodes_u
    assert 1 in nodes_v, nodes_v
    assert 1 in nodes, nodes
    assert len(nodes_u) == 3, nodes_u
    assert len(nodes_v) == 3, nodes_v
    assert nodes_u != nodes_v, (nodes_u, nodes_v)
    assert len(nodes) == 4, nodes
    assert nodes == nodes_u.union(nodes_v), (
        nodes, b._succ)
    # no roots
    roots = []
    nodes = b.descendants(roots)
    assert len(nodes) == 0, nodes

def test_sat_iter():
    # x & y
    g = x_and_y()
    u = 2
    s = [{'x': 1, 'y': 1}]
    compare_iter_to_list_of_sets(u, g, s)
    # x | y
    g = x_or_y()
    u = 2
    s = [{'x': 1}, {'x': 0, 'y': 1}]
    compare_iter_to_list_of_sets(u, g, s)
    # x & !y
    g = x_and_not_y()
    u = -2
    s = [{'x': 1, 'y': 0}]
    compare_iter_to_list_of_sets(u, g, s)
    # gaps in order
    order = {'x': 0, 'y': 1, 'z': 2}
    bdd = BDD(order)
    u = bdd.add_expr('x & z')
    (m,) = bdd.sat_iter(u)
    assert m == {'x': 1, 'z': 1}, m

def two_vars_xy():
    ordering = {'x': 0, 'y': 1}
    g = BDD(ordering)
    u = 2
    t = (0, -1, 1)
    g._succ[u] = t
    g._pred[t] = u
    g._ref[u] = 1
    u = 3
    t = (1, -1, 1)
    g._succ[u] = t
    g._pred[t] = u
    g._ref[u] = 1
    g._min_free = u + 1
    return g

def load(fname):
    """Return a `BDD` loaded from DDDMP file `fname`.

    If no `.orderedvarnames` appear in the file,
    then `.suppvarnames` and `.permids` are used instead.
    In the second case, the variable levels contains blanks.
    To avoid blanks, the levels are re-indexed here.
    This has no effect if `.orderedvarnames` appears in the file.

    DDDMP files are dumped by [CUDD](http://vlsi.colorado.edu/~fabio/CUDD/).
    """
    parser = Parser()
    bdd_succ, n_vars, ordering, roots = parser.parse(fname)
    # reindex to ensure no blanks
    perm = {k: var for var, k in ordering.iteritems()}
    perm = {i: perm[k] for i, k in enumerate(sorted(perm))}
    new_ordering = {var: k for k, var in perm.iteritems()}
    old2new = {ordering[var]: new_ordering[var] for var in ordering}
    # convert
    bdd = BDD(new_ordering)
    umap = {-1: -1, 1: 1}
    for j in xrange(len(new_ordering) - 1, -1, -1):
        for u, (k, v, w) in bdd_succ.iteritems():
            # terminal ?
            if v is None:
                assert w is None, w
                continue
            # non-terminal
            i = old2new[k]
            if i != j:
                continue
            p, q = umap[abs(v)], umap[w]
            if v < 0:
                p = -p
            r = bdd.find_or_add(i, p, q)
            umap[abs(u)] = r
    bdd.roots.update(roots)
    return bdd