563 lines
20 KiB
Python
563 lines
20 KiB
Python
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from itertools import permutations
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from sympy.core.expr import unchanged
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from sympy.core.numbers import Integer
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from sympy.core.relational import Eq
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from sympy.core.symbol import Symbol
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from sympy.core.singleton import S
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from sympy.combinatorics.permutations import \
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Permutation, _af_parity, _af_rmul, _af_rmuln, AppliedPermutation, Cycle
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from sympy.printing import sstr, srepr, pretty, latex
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from sympy.testing.pytest import raises, warns_deprecated_sympy
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rmul = Permutation.rmul
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a = Symbol('a', integer=True)
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def test_Permutation():
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# don't auto fill 0
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raises(ValueError, lambda: Permutation([1]))
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p = Permutation([0, 1, 2, 3])
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# call as bijective
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assert [p(i) for i in range(p.size)] == list(p)
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# call as operator
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assert p(list(range(p.size))) == list(p)
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# call as function
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assert list(p(1, 2)) == [0, 2, 1, 3]
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raises(TypeError, lambda: p(-1))
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raises(TypeError, lambda: p(5))
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# conversion to list
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assert list(p) == list(range(4))
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assert Permutation(size=4) == Permutation(3)
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assert Permutation(Permutation(3), size=5) == Permutation(4)
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# cycle form with size
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assert Permutation([[1, 2]], size=4) == Permutation([[1, 2], [0], [3]])
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# random generation
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assert Permutation.random(2) in (Permutation([1, 0]), Permutation([0, 1]))
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p = Permutation([2, 5, 1, 6, 3, 0, 4])
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q = Permutation([[1], [0, 3, 5, 6, 2, 4]])
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assert len({p, p}) == 1
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r = Permutation([1, 3, 2, 0, 4, 6, 5])
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ans = Permutation(_af_rmuln(*[w.array_form for w in (p, q, r)])).array_form
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assert rmul(p, q, r).array_form == ans
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# make sure no other permutation of p, q, r could have given
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# that answer
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for a, b, c in permutations((p, q, r)):
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if (a, b, c) == (p, q, r):
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continue
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assert rmul(a, b, c).array_form != ans
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assert p.support() == list(range(7))
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assert q.support() == [0, 2, 3, 4, 5, 6]
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assert Permutation(p.cyclic_form).array_form == p.array_form
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assert p.cardinality == 5040
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assert q.cardinality == 5040
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assert q.cycles == 2
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assert rmul(q, p) == Permutation([4, 6, 1, 2, 5, 3, 0])
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assert rmul(p, q) == Permutation([6, 5, 3, 0, 2, 4, 1])
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assert _af_rmul(p.array_form, q.array_form) == \
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[6, 5, 3, 0, 2, 4, 1]
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assert rmul(Permutation([[1, 2, 3], [0, 4]]),
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Permutation([[1, 2, 4], [0], [3]])).cyclic_form == \
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[[0, 4, 2], [1, 3]]
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assert q.array_form == [3, 1, 4, 5, 0, 6, 2]
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assert q.cyclic_form == [[0, 3, 5, 6, 2, 4]]
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assert q.full_cyclic_form == [[0, 3, 5, 6, 2, 4], [1]]
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assert p.cyclic_form == [[0, 2, 1, 5], [3, 6, 4]]
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t = p.transpositions()
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assert t == [(0, 5), (0, 1), (0, 2), (3, 4), (3, 6)]
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assert Permutation.rmul(*[Permutation(Cycle(*ti)) for ti in (t)])
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assert Permutation([1, 0]).transpositions() == [(0, 1)]
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assert p**13 == p
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assert q**0 == Permutation(list(range(q.size)))
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assert q**-2 == ~q**2
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assert q**2 == Permutation([5, 1, 0, 6, 3, 2, 4])
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assert q**3 == q**2*q
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assert q**4 == q**2*q**2
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a = Permutation(1, 3)
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b = Permutation(2, 0, 3)
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I = Permutation(3)
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assert ~a == a**-1
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assert a*~a == I
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assert a*b**-1 == a*~b
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ans = Permutation(0, 5, 3, 1, 6)(2, 4)
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assert (p + q.rank()).rank() == ans.rank()
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assert (p + q.rank())._rank == ans.rank()
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assert (q + p.rank()).rank() == ans.rank()
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raises(TypeError, lambda: p + Permutation(list(range(10))))
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assert (p - q.rank()).rank() == Permutation(0, 6, 3, 1, 2, 5, 4).rank()
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assert p.rank() - q.rank() < 0 # for coverage: make sure mod is used
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assert (q - p.rank()).rank() == Permutation(1, 4, 6, 2)(3, 5).rank()
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assert p*q == Permutation(_af_rmuln(*[list(w) for w in (q, p)]))
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assert p*Permutation([]) == p
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assert Permutation([])*p == p
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assert p*Permutation([[0, 1]]) == Permutation([2, 5, 0, 6, 3, 1, 4])
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assert Permutation([[0, 1]])*p == Permutation([5, 2, 1, 6, 3, 0, 4])
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pq = p ^ q
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assert pq == Permutation([5, 6, 0, 4, 1, 2, 3])
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assert pq == rmul(q, p, ~q)
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qp = q ^ p
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assert qp == Permutation([4, 3, 6, 2, 1, 5, 0])
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assert qp == rmul(p, q, ~p)
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raises(ValueError, lambda: p ^ Permutation([]))
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assert p.commutator(q) == Permutation(0, 1, 3, 4, 6, 5, 2)
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assert q.commutator(p) == Permutation(0, 2, 5, 6, 4, 3, 1)
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assert p.commutator(q) == ~q.commutator(p)
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raises(ValueError, lambda: p.commutator(Permutation([])))
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assert len(p.atoms()) == 7
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assert q.atoms() == {0, 1, 2, 3, 4, 5, 6}
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assert p.inversion_vector() == [2, 4, 1, 3, 1, 0]
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assert q.inversion_vector() == [3, 1, 2, 2, 0, 1]
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assert Permutation.from_inversion_vector(p.inversion_vector()) == p
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assert Permutation.from_inversion_vector(q.inversion_vector()).array_form\
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== q.array_form
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raises(ValueError, lambda: Permutation.from_inversion_vector([0, 2]))
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assert Permutation(list(range(500, -1, -1))).inversions() == 125250
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s = Permutation([0, 4, 1, 3, 2])
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assert s.parity() == 0
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_ = s.cyclic_form # needed to create a value for _cyclic_form
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assert len(s._cyclic_form) != s.size and s.parity() == 0
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assert not s.is_odd
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assert s.is_even
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assert Permutation([0, 1, 4, 3, 2]).parity() == 1
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assert _af_parity([0, 4, 1, 3, 2]) == 0
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assert _af_parity([0, 1, 4, 3, 2]) == 1
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s = Permutation([0])
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assert s.is_Singleton
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assert Permutation([]).is_Empty
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r = Permutation([3, 2, 1, 0])
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assert (r**2).is_Identity
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assert rmul(~p, p).is_Identity
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assert (~p)**13 == Permutation([5, 2, 0, 4, 6, 1, 3])
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assert ~(r**2).is_Identity
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assert p.max() == 6
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assert p.min() == 0
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q = Permutation([[6], [5], [0, 1, 2, 3, 4]])
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assert q.max() == 4
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assert q.min() == 0
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p = Permutation([1, 5, 2, 0, 3, 6, 4])
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q = Permutation([[1, 2, 3, 5, 6], [0, 4]])
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assert p.ascents() == [0, 3, 4]
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assert q.ascents() == [1, 2, 4]
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assert r.ascents() == []
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assert p.descents() == [1, 2, 5]
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assert q.descents() == [0, 3, 5]
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assert Permutation(r.descents()).is_Identity
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assert p.inversions() == 7
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# test the merge-sort with a longer permutation
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big = list(p) + list(range(p.max() + 1, p.max() + 130))
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assert Permutation(big).inversions() == 7
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assert p.signature() == -1
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assert q.inversions() == 11
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assert q.signature() == -1
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assert rmul(p, ~p).inversions() == 0
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assert rmul(p, ~p).signature() == 1
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assert p.order() == 6
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assert q.order() == 10
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assert (p**(p.order())).is_Identity
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assert p.length() == 6
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assert q.length() == 7
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assert r.length() == 4
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assert p.runs() == [[1, 5], [2], [0, 3, 6], [4]]
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assert q.runs() == [[4], [2, 3, 5], [0, 6], [1]]
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assert r.runs() == [[3], [2], [1], [0]]
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assert p.index() == 8
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assert q.index() == 8
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assert r.index() == 3
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assert p.get_precedence_distance(q) == q.get_precedence_distance(p)
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assert p.get_adjacency_distance(q) == p.get_adjacency_distance(q)
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assert p.get_positional_distance(q) == p.get_positional_distance(q)
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p = Permutation([0, 1, 2, 3])
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q = Permutation([3, 2, 1, 0])
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assert p.get_precedence_distance(q) == 6
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assert p.get_adjacency_distance(q) == 3
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assert p.get_positional_distance(q) == 8
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p = Permutation([0, 3, 1, 2, 4])
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q = Permutation.josephus(4, 5, 2)
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assert p.get_adjacency_distance(q) == 3
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raises(ValueError, lambda: p.get_adjacency_distance(Permutation([])))
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raises(ValueError, lambda: p.get_positional_distance(Permutation([])))
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raises(ValueError, lambda: p.get_precedence_distance(Permutation([])))
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a = [Permutation.unrank_nonlex(4, i) for i in range(5)]
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iden = Permutation([0, 1, 2, 3])
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for i in range(5):
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for j in range(i + 1, 5):
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assert a[i].commutes_with(a[j]) == \
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(rmul(a[i], a[j]) == rmul(a[j], a[i]))
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if a[i].commutes_with(a[j]):
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assert a[i].commutator(a[j]) == iden
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assert a[j].commutator(a[i]) == iden
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a = Permutation(3)
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b = Permutation(0, 6, 3)(1, 2)
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assert a.cycle_structure == {1: 4}
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assert b.cycle_structure == {2: 1, 3: 1, 1: 2}
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# issue 11130
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raises(ValueError, lambda: Permutation(3, size=3))
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raises(ValueError, lambda: Permutation([1, 2, 0, 3], size=3))
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def test_Permutation_subclassing():
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# Subclass that adds permutation application on iterables
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class CustomPermutation(Permutation):
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def __call__(self, *i):
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try:
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return super().__call__(*i)
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except TypeError:
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pass
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try:
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perm_obj = i[0]
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return [self._array_form[j] for j in perm_obj]
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except TypeError:
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raise TypeError('unrecognized argument')
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def __eq__(self, other):
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if isinstance(other, Permutation):
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return self._hashable_content() == other._hashable_content()
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else:
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return super().__eq__(other)
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def __hash__(self):
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return super().__hash__()
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p = CustomPermutation([1, 2, 3, 0])
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q = Permutation([1, 2, 3, 0])
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assert p == q
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raises(TypeError, lambda: q([1, 2]))
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assert [2, 3] == p([1, 2])
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assert type(p * q) == CustomPermutation
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assert type(q * p) == Permutation # True because q.__mul__(p) is called!
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# Run all tests for the Permutation class also on the subclass
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def wrapped_test_Permutation():
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# Monkeypatch the class definition in the globals
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globals()['__Perm'] = globals()['Permutation']
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globals()['Permutation'] = CustomPermutation
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test_Permutation()
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globals()['Permutation'] = globals()['__Perm'] # Restore
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del globals()['__Perm']
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wrapped_test_Permutation()
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def test_josephus():
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assert Permutation.josephus(4, 6, 1) == Permutation([3, 1, 0, 2, 5, 4])
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assert Permutation.josephus(1, 5, 1).is_Identity
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def test_ranking():
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assert Permutation.unrank_lex(5, 10).rank() == 10
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p = Permutation.unrank_lex(15, 225)
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assert p.rank() == 225
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p1 = p.next_lex()
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assert p1.rank() == 226
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assert Permutation.unrank_lex(15, 225).rank() == 225
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assert Permutation.unrank_lex(10, 0).is_Identity
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p = Permutation.unrank_lex(4, 23)
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assert p.rank() == 23
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assert p.array_form == [3, 2, 1, 0]
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assert p.next_lex() is None
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p = Permutation([1, 5, 2, 0, 3, 6, 4])
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q = Permutation([[1, 2, 3, 5, 6], [0, 4]])
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a = [Permutation.unrank_trotterjohnson(4, i).array_form for i in range(5)]
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assert a == [[0, 1, 2, 3], [0, 1, 3, 2], [0, 3, 1, 2], [3, 0, 1,
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2], [3, 0, 2, 1] ]
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assert [Permutation(pa).rank_trotterjohnson() for pa in a] == list(range(5))
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assert Permutation([0, 1, 2, 3]).next_trotterjohnson() == \
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Permutation([0, 1, 3, 2])
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assert q.rank_trotterjohnson() == 2283
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assert p.rank_trotterjohnson() == 3389
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assert Permutation([1, 0]).rank_trotterjohnson() == 1
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a = Permutation(list(range(3)))
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b = a
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l = []
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tj = []
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for i in range(6):
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l.append(a)
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tj.append(b)
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a = a.next_lex()
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b = b.next_trotterjohnson()
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assert a == b is None
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assert {tuple(a) for a in l} == {tuple(a) for a in tj}
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p = Permutation([2, 5, 1, 6, 3, 0, 4])
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q = Permutation([[6], [5], [0, 1, 2, 3, 4]])
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assert p.rank() == 1964
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assert q.rank() == 870
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assert Permutation([]).rank_nonlex() == 0
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prank = p.rank_nonlex()
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assert prank == 1600
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assert Permutation.unrank_nonlex(7, 1600) == p
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qrank = q.rank_nonlex()
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assert qrank == 41
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assert Permutation.unrank_nonlex(7, 41) == Permutation(q.array_form)
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a = [Permutation.unrank_nonlex(4, i).array_form for i in range(24)]
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assert a == [
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[1, 2, 3, 0], [3, 2, 0, 1], [1, 3, 0, 2], [1, 2, 0, 3], [2, 3, 1, 0],
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[2, 0, 3, 1], [3, 0, 1, 2], [2, 0, 1, 3], [1, 3, 2, 0], [3, 0, 2, 1],
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[1, 0, 3, 2], [1, 0, 2, 3], [2, 1, 3, 0], [2, 3, 0, 1], [3, 1, 0, 2],
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[2, 1, 0, 3], [3, 2, 1, 0], [0, 2, 3, 1], [0, 3, 1, 2], [0, 2, 1, 3],
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[3, 1, 2, 0], [0, 3, 2, 1], [0, 1, 3, 2], [0, 1, 2, 3]]
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N = 10
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p1 = Permutation(a[0])
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for i in range(1, N+1):
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p1 = p1*Permutation(a[i])
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p2 = Permutation.rmul_with_af(*[Permutation(h) for h in a[N::-1]])
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assert p1 == p2
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ok = []
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p = Permutation([1, 0])
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for i in range(3):
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ok.append(p.array_form)
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p = p.next_nonlex()
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if p is None:
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ok.append(None)
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break
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assert ok == [[1, 0], [0, 1], None]
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assert Permutation([3, 2, 0, 1]).next_nonlex() == Permutation([1, 3, 0, 2])
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assert [Permutation(pa).rank_nonlex() for pa in a] == list(range(24))
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def test_mul():
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a, b = [0, 2, 1, 3], [0, 1, 3, 2]
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assert _af_rmul(a, b) == [0, 2, 3, 1]
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assert _af_rmuln(a, b, list(range(4))) == [0, 2, 3, 1]
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||
|
assert rmul(Permutation(a), Permutation(b)).array_form == [0, 2, 3, 1]
|
||
|
|
||
|
a = Permutation([0, 2, 1, 3])
|
||
|
b = (0, 1, 3, 2)
|
||
|
c = (3, 1, 2, 0)
|
||
|
assert Permutation.rmul(a, b, c) == Permutation([1, 2, 3, 0])
|
||
|
assert Permutation.rmul(a, c) == Permutation([3, 2, 1, 0])
|
||
|
raises(TypeError, lambda: Permutation.rmul(b, c))
|
||
|
|
||
|
n = 6
|
||
|
m = 8
|
||
|
a = [Permutation.unrank_nonlex(n, i).array_form for i in range(m)]
|
||
|
h = list(range(n))
|
||
|
for i in range(m):
|
||
|
h = _af_rmul(h, a[i])
|
||
|
h2 = _af_rmuln(*a[:i + 1])
|
||
|
assert h == h2
|
||
|
|
||
|
|
||
|
def test_args():
|
||
|
p = Permutation([(0, 3, 1, 2), (4, 5)])
|
||
|
assert p._cyclic_form is None
|
||
|
assert Permutation(p) == p
|
||
|
assert p.cyclic_form == [[0, 3, 1, 2], [4, 5]]
|
||
|
assert p._array_form == [3, 2, 0, 1, 5, 4]
|
||
|
p = Permutation((0, 3, 1, 2))
|
||
|
assert p._cyclic_form is None
|
||
|
assert p._array_form == [0, 3, 1, 2]
|
||
|
assert Permutation([0]) == Permutation((0, ))
|
||
|
assert Permutation([[0], [1]]) == Permutation(((0, ), (1, ))) == \
|
||
|
Permutation(((0, ), [1]))
|
||
|
assert Permutation([[1, 2]]) == Permutation([0, 2, 1])
|
||
|
assert Permutation([[1], [4, 2]]) == Permutation([0, 1, 4, 3, 2])
|
||
|
assert Permutation([[1], [4, 2]], size=1) == Permutation([0, 1, 4, 3, 2])
|
||
|
assert Permutation(
|
||
|
[[1], [4, 2]], size=6) == Permutation([0, 1, 4, 3, 2, 5])
|
||
|
assert Permutation([[0, 1], [0, 2]]) == Permutation(0, 1, 2)
|
||
|
assert Permutation([], size=3) == Permutation([0, 1, 2])
|
||
|
assert Permutation(3).list(5) == [0, 1, 2, 3, 4]
|
||
|
assert Permutation(3).list(-1) == []
|
||
|
assert Permutation(5)(1, 2).list(-1) == [0, 2, 1]
|
||
|
assert Permutation(5)(1, 2).list() == [0, 2, 1, 3, 4, 5]
|
||
|
raises(ValueError, lambda: Permutation([1, 2], [0]))
|
||
|
# enclosing brackets needed
|
||
|
raises(ValueError, lambda: Permutation([[1, 2], 0]))
|
||
|
# enclosing brackets needed on 0
|
||
|
raises(ValueError, lambda: Permutation([1, 1, 0]))
|
||
|
raises(ValueError, lambda: Permutation([4, 5], size=10)) # where are 0-3?
|
||
|
# but this is ok because cycles imply that only those listed moved
|
||
|
assert Permutation(4, 5) == Permutation([0, 1, 2, 3, 5, 4])
|
||
|
|
||
|
|
||
|
def test_Cycle():
|
||
|
assert str(Cycle()) == '()'
|
||
|
assert Cycle(Cycle(1,2)) == Cycle(1, 2)
|
||
|
assert Cycle(1,2).copy() == Cycle(1,2)
|
||
|
assert list(Cycle(1, 3, 2)) == [0, 3, 1, 2]
|
||
|
assert Cycle(1, 2)(2, 3) == Cycle(1, 3, 2)
|
||
|
assert Cycle(1, 2)(2, 3)(4, 5) == Cycle(1, 3, 2)(4, 5)
|
||
|
assert Permutation(Cycle(1, 2)(2, 1, 0, 3)).cyclic_form, Cycle(0, 2, 1)
|
||
|
raises(ValueError, lambda: Cycle().list())
|
||
|
assert Cycle(1, 2).list() == [0, 2, 1]
|
||
|
assert Cycle(1, 2).list(4) == [0, 2, 1, 3]
|
||
|
assert Cycle(3).list(2) == [0, 1]
|
||
|
assert Cycle(3).list(6) == [0, 1, 2, 3, 4, 5]
|
||
|
assert Permutation(Cycle(1, 2), size=4) == \
|
||
|
Permutation([0, 2, 1, 3])
|
||
|
assert str(Cycle(1, 2)(4, 5)) == '(1 2)(4 5)'
|
||
|
assert str(Cycle(1, 2)) == '(1 2)'
|
||
|
assert Cycle(Permutation(list(range(3)))) == Cycle()
|
||
|
assert Cycle(1, 2).list() == [0, 2, 1]
|
||
|
assert Cycle(1, 2).list(4) == [0, 2, 1, 3]
|
||
|
assert Cycle().size == 0
|
||
|
raises(ValueError, lambda: Cycle((1, 2)))
|
||
|
raises(ValueError, lambda: Cycle(1, 2, 1))
|
||
|
raises(TypeError, lambda: Cycle(1, 2)*{})
|
||
|
raises(ValueError, lambda: Cycle(4)[a])
|
||
|
raises(ValueError, lambda: Cycle(2, -4, 3))
|
||
|
|
||
|
# check round-trip
|
||
|
p = Permutation([[1, 2], [4, 3]], size=5)
|
||
|
assert Permutation(Cycle(p)) == p
|
||
|
|
||
|
|
||
|
def test_from_sequence():
|
||
|
assert Permutation.from_sequence('SymPy') == Permutation(4)(0, 1, 3)
|
||
|
assert Permutation.from_sequence('SymPy', key=lambda x: x.lower()) == \
|
||
|
Permutation(4)(0, 2)(1, 3)
|
||
|
|
||
|
|
||
|
def test_resize():
|
||
|
p = Permutation(0, 1, 2)
|
||
|
assert p.resize(5) == Permutation(0, 1, 2, size=5)
|
||
|
assert p.resize(4) == Permutation(0, 1, 2, size=4)
|
||
|
assert p.resize(3) == p
|
||
|
raises(ValueError, lambda: p.resize(2))
|
||
|
|
||
|
p = Permutation(0, 1, 2)(3, 4)(5, 6)
|
||
|
assert p.resize(3) == Permutation(0, 1, 2)
|
||
|
raises(ValueError, lambda: p.resize(4))
|
||
|
|
||
|
|
||
|
def test_printing_cyclic():
|
||
|
p1 = Permutation([0, 2, 1])
|
||
|
assert repr(p1) == 'Permutation(1, 2)'
|
||
|
assert str(p1) == '(1 2)'
|
||
|
p2 = Permutation()
|
||
|
assert repr(p2) == 'Permutation()'
|
||
|
assert str(p2) == '()'
|
||
|
p3 = Permutation([1, 2, 0, 3])
|
||
|
assert repr(p3) == 'Permutation(3)(0, 1, 2)'
|
||
|
|
||
|
|
||
|
def test_printing_non_cyclic():
|
||
|
p1 = Permutation([0, 1, 2, 3, 4, 5])
|
||
|
assert srepr(p1, perm_cyclic=False) == 'Permutation([], size=6)'
|
||
|
assert sstr(p1, perm_cyclic=False) == 'Permutation([], size=6)'
|
||
|
p2 = Permutation([0, 1, 2])
|
||
|
assert srepr(p2, perm_cyclic=False) == 'Permutation([0, 1, 2])'
|
||
|
assert sstr(p2, perm_cyclic=False) == 'Permutation([0, 1, 2])'
|
||
|
|
||
|
p3 = Permutation([0, 2, 1])
|
||
|
assert srepr(p3, perm_cyclic=False) == 'Permutation([0, 2, 1])'
|
||
|
assert sstr(p3, perm_cyclic=False) == 'Permutation([0, 2, 1])'
|
||
|
p4 = Permutation([0, 1, 3, 2, 4, 5, 6, 7])
|
||
|
assert srepr(p4, perm_cyclic=False) == 'Permutation([0, 1, 3, 2], size=8)'
|
||
|
|
||
|
|
||
|
def test_deprecated_print_cyclic():
|
||
|
p = Permutation(0, 1, 2)
|
||
|
try:
|
||
|
Permutation.print_cyclic = True
|
||
|
with warns_deprecated_sympy():
|
||
|
assert sstr(p) == '(0 1 2)'
|
||
|
with warns_deprecated_sympy():
|
||
|
assert srepr(p) == 'Permutation(0, 1, 2)'
|
||
|
with warns_deprecated_sympy():
|
||
|
assert pretty(p) == '(0 1 2)'
|
||
|
with warns_deprecated_sympy():
|
||
|
assert latex(p) == r'\left( 0\; 1\; 2\right)'
|
||
|
|
||
|
Permutation.print_cyclic = False
|
||
|
with warns_deprecated_sympy():
|
||
|
assert sstr(p) == 'Permutation([1, 2, 0])'
|
||
|
with warns_deprecated_sympy():
|
||
|
assert srepr(p) == 'Permutation([1, 2, 0])'
|
||
|
with warns_deprecated_sympy():
|
||
|
assert pretty(p, use_unicode=False) == '/0 1 2\\\n\\1 2 0/'
|
||
|
with warns_deprecated_sympy():
|
||
|
assert latex(p) == \
|
||
|
r'\begin{pmatrix} 0 & 1 & 2 \\ 1 & 2 & 0 \end{pmatrix}'
|
||
|
finally:
|
||
|
Permutation.print_cyclic = None
|
||
|
|
||
|
|
||
|
def test_permutation_equality():
|
||
|
a = Permutation(0, 1, 2)
|
||
|
b = Permutation(0, 1, 2)
|
||
|
assert Eq(a, b) is S.true
|
||
|
c = Permutation(0, 2, 1)
|
||
|
assert Eq(a, c) is S.false
|
||
|
|
||
|
d = Permutation(0, 1, 2, size=4)
|
||
|
assert unchanged(Eq, a, d)
|
||
|
e = Permutation(0, 2, 1, size=4)
|
||
|
assert unchanged(Eq, a, e)
|
||
|
|
||
|
i = Permutation()
|
||
|
assert unchanged(Eq, i, 0)
|
||
|
assert unchanged(Eq, 0, i)
|
||
|
|
||
|
|
||
|
def test_issue_17661():
|
||
|
c1 = Cycle(1,2)
|
||
|
c2 = Cycle(1,2)
|
||
|
assert c1 == c2
|
||
|
assert repr(c1) == 'Cycle(1, 2)'
|
||
|
assert c1 == c2
|
||
|
|
||
|
|
||
|
def test_permutation_apply():
|
||
|
x = Symbol('x')
|
||
|
p = Permutation(0, 1, 2)
|
||
|
assert p.apply(0) == 1
|
||
|
assert isinstance(p.apply(0), Integer)
|
||
|
assert p.apply(x) == AppliedPermutation(p, x)
|
||
|
assert AppliedPermutation(p, x).subs(x, 0) == 1
|
||
|
|
||
|
x = Symbol('x', integer=False)
|
||
|
raises(NotImplementedError, lambda: p.apply(x))
|
||
|
x = Symbol('x', negative=True)
|
||
|
raises(NotImplementedError, lambda: p.apply(x))
|
||
|
|
||
|
|
||
|
def test_AppliedPermutation():
|
||
|
x = Symbol('x')
|
||
|
p = Permutation(0, 1, 2)
|
||
|
raises(ValueError, lambda: AppliedPermutation((0, 1, 2), x))
|
||
|
assert AppliedPermutation(p, 1, evaluate=True) == 2
|
||
|
assert AppliedPermutation(p, 1, evaluate=False).__class__ == \
|
||
|
AppliedPermutation
|