Affine Permutations#
- class sage.combinat.affine_permutation.AffinePermutation(parent, lst, check=True)[source]#
Bases:
ClonableArray
An affine permutation, represented in the window notation, and considered as a bijection from \(\ZZ\) to \(\ZZ\).
EXAMPLES:
sage: A = AffinePermutationGroup(['A',7,1]) sage: p = A([3, -1, 0, 6, 5, 4, 10, 9]) sage: p Type A affine permutation with window [3, -1, 0, 6, 5, 4, 10, 9]
>>> from sage.all import * >>> A = AffinePermutationGroup(['A',Integer(7),Integer(1)]) >>> p = A([Integer(3), -Integer(1), Integer(0), Integer(6), Integer(5), Integer(4), Integer(10), Integer(9)]) >>> p Type A affine permutation with window [3, -1, 0, 6, 5, 4, 10, 9]
- apply_simple_reflection(i, side='right')[source]#
Apply a simple reflection.
INPUT:
i
– an integerside
– (default:'right'
) determines whether to apply the reflection on the'right'
or'left'
EXAMPLES:
sage: p = AffinePermutationGroup(['A',7,1])([3, -1, 0, 6, 5, 4, 10, 9]) sage: p.apply_simple_reflection(3) Type A affine permutation with window [3, -1, 6, 0, 5, 4, 10, 9] sage: p.apply_simple_reflection(11) Type A affine permutation with window [3, -1, 6, 0, 5, 4, 10, 9] sage: p.apply_simple_reflection(3, 'left') Type A affine permutation with window [4, -1, 0, 6, 5, 3, 10, 9] sage: p.apply_simple_reflection(11, 'left') Type A affine permutation with window [4, -1, 0, 6, 5, 3, 10, 9]
>>> from sage.all import * >>> p = AffinePermutationGroup(['A',Integer(7),Integer(1)])([Integer(3), -Integer(1), Integer(0), Integer(6), Integer(5), Integer(4), Integer(10), Integer(9)]) >>> p.apply_simple_reflection(Integer(3)) Type A affine permutation with window [3, -1, 6, 0, 5, 4, 10, 9] >>> p.apply_simple_reflection(Integer(11)) Type A affine permutation with window [3, -1, 6, 0, 5, 4, 10, 9] >>> p.apply_simple_reflection(Integer(3), 'left') Type A affine permutation with window [4, -1, 0, 6, 5, 3, 10, 9] >>> p.apply_simple_reflection(Integer(11), 'left') Type A affine permutation with window [4, -1, 0, 6, 5, 3, 10, 9]
- grassmannian_quotient(i=0, side='right')[source]#
Return the Grassmannian quotient.
Factors
self
into a unique product of a Grassmannian and a finite-type element. Returns a tuple containing the Grassmannian and finite elements, in order according toside
.INPUT:
i
– (default: 0) an element of the index set; the descent checked for
EXAMPLES:
sage: A = AffinePermutationGroup(['A',7,1]) sage: p=A([3, -1, 0, 6, 5, 4, 10, 9]) sage: gq=p.grassmannian_quotient() sage: gq (Type A affine permutation with window [-1, 0, 3, 4, 5, 6, 9, 10], Type A affine permutation with window [3, 1, 2, 6, 5, 4, 8, 7]) sage: gq[0].is_i_grassmannian() True sage: 0 not in gq[1].reduced_word() True sage: prod(gq)==p True sage: gqLeft=p.grassmannian_quotient(side='left') sage: 0 not in gqLeft[0].reduced_word() True sage: gqLeft[1].is_i_grassmannian(side='left') True sage: prod(gqLeft)==p True
>>> from sage.all import * >>> A = AffinePermutationGroup(['A',Integer(7),Integer(1)]) >>> p=A([Integer(3), -Integer(1), Integer(0), Integer(6), Integer(5), Integer(4), Integer(10), Integer(9)]) >>> gq=p.grassmannian_quotient() >>> gq (Type A affine permutation with window [-1, 0, 3, 4, 5, 6, 9, 10], Type A affine permutation with window [3, 1, 2, 6, 5, 4, 8, 7]) >>> gq[Integer(0)].is_i_grassmannian() True >>> Integer(0) not in gq[Integer(1)].reduced_word() True >>> prod(gq)==p True >>> gqLeft=p.grassmannian_quotient(side='left') >>> Integer(0) not in gqLeft[Integer(0)].reduced_word() True >>> gqLeft[Integer(1)].is_i_grassmannian(side='left') True >>> prod(gqLeft)==p True
- index_set()[source]#
Index set of the affine permutation group.
EXAMPLES:
sage: A = AffinePermutationGroup(['A',7,1]) sage: A.index_set() (0, 1, 2, 3, 4, 5, 6, 7)
>>> from sage.all import * >>> A = AffinePermutationGroup(['A',Integer(7),Integer(1)]) >>> A.index_set() (0, 1, 2, 3, 4, 5, 6, 7)
- is_i_grassmannian(i=0, side='right')[source]#
Test whether
self
is \(i\)-grassmannian, i.e., either is the identity or hasi
as the sole descent.INPUT:
i
– an element of the index setside
– determines the side on which to check the descents
EXAMPLES:
sage: A = AffinePermutationGroup(['A',7,1]) sage: p=A([3, -1, 0, 6, 5, 4, 10, 9]) sage: p.is_i_grassmannian() False sage: q=A.from_word([3,2,1,0]) sage: q.is_i_grassmannian() True sage: q=A.from_word([2,3,4,5]) sage: q.is_i_grassmannian(5) True sage: q.is_i_grassmannian(2, side='left') True
>>> from sage.all import * >>> A = AffinePermutationGroup(['A',Integer(7),Integer(1)]) >>> p=A([Integer(3), -Integer(1), Integer(0), Integer(6), Integer(5), Integer(4), Integer(10), Integer(9)]) >>> p.is_i_grassmannian() False >>> q=A.from_word([Integer(3),Integer(2),Integer(1),Integer(0)]) >>> q.is_i_grassmannian() True >>> q=A.from_word([Integer(2),Integer(3),Integer(4),Integer(5)]) >>> q.is_i_grassmannian(Integer(5)) True >>> q.is_i_grassmannian(Integer(2), side='left') True
- is_one()[source]#
Tests whether the affine permutation is the identity.
EXAMPLES:
sage: A = AffinePermutationGroup(['A',7,1]) sage: p=A([3, -1, 0, 6, 5, 4, 10, 9]) sage: p.is_one() False sage: q=A.one() sage: q.is_one() True
>>> from sage.all import * >>> A = AffinePermutationGroup(['A',Integer(7),Integer(1)]) >>> p=A([Integer(3), -Integer(1), Integer(0), Integer(6), Integer(5), Integer(4), Integer(10), Integer(9)]) >>> p.is_one() False >>> q=A.one() >>> q.is_one() True
- lower_covers(side='right')[source]#
Return lower covers of
self
.The set of affine permutations of one less length related by multiplication by a simple transposition on the indicated side. These are the elements that
self
covers in weak order.EXAMPLES:
sage: A = AffinePermutationGroup(['A',7,1]) sage: p=A([3, -1, 0, 6, 5, 4, 10, 9]) sage: p.lower_covers() [Type A affine permutation with window [-1, 3, 0, 6, 5, 4, 10, 9], Type A affine permutation with window [3, -1, 0, 5, 6, 4, 10, 9], Type A affine permutation with window [3, -1, 0, 6, 4, 5, 10, 9], Type A affine permutation with window [3, -1, 0, 6, 5, 4, 9, 10]]
>>> from sage.all import * >>> A = AffinePermutationGroup(['A',Integer(7),Integer(1)]) >>> p=A([Integer(3), -Integer(1), Integer(0), Integer(6), Integer(5), Integer(4), Integer(10), Integer(9)]) >>> p.lower_covers() [Type A affine permutation with window [-1, 3, 0, 6, 5, 4, 10, 9], Type A affine permutation with window [3, -1, 0, 5, 6, 4, 10, 9], Type A affine permutation with window [3, -1, 0, 6, 4, 5, 10, 9], Type A affine permutation with window [3, -1, 0, 6, 5, 4, 9, 10]]
- reduced_word()[source]#
Returns a reduced word for the affine permutation.
EXAMPLES:
sage: A = AffinePermutationGroup(['A',7,1]) sage: p=A([3, -1, 0, 6, 5, 4, 10, 9]) sage: p.reduced_word() [0, 7, 4, 1, 0, 7, 5, 4, 2, 1]
>>> from sage.all import * >>> A = AffinePermutationGroup(['A',Integer(7),Integer(1)]) >>> p=A([Integer(3), -Integer(1), Integer(0), Integer(6), Integer(5), Integer(4), Integer(10), Integer(9)]) >>> p.reduced_word() [0, 7, 4, 1, 0, 7, 5, 4, 2, 1]
- signature()[source]#
Signature of the affine permutation, \((-1)^l\), where \(l\) is the length of the permutation.
EXAMPLES:
sage: A = AffinePermutationGroup(['A',7,1]) sage: p=A([3, -1, 0, 6, 5, 4, 10, 9]) sage: p.signature() 1
>>> from sage.all import * >>> A = AffinePermutationGroup(['A',Integer(7),Integer(1)]) >>> p=A([Integer(3), -Integer(1), Integer(0), Integer(6), Integer(5), Integer(4), Integer(10), Integer(9)]) >>> p.signature() 1
- to_weyl_group_element()[source]#
The affine Weyl group element corresponding to the affine permutation.
EXAMPLES:
sage: A = AffinePermutationGroup(['A',7,1]) sage: p=A([3, -1, 0, 6, 5, 4, 10, 9]) sage: p.to_weyl_group_element() [ 0 -1 0 1 0 0 1 0] [ 1 -1 0 1 0 0 1 -1] [ 1 -1 0 1 0 0 0 0] [ 0 0 0 1 0 0 0 0] [ 0 0 0 1 0 -1 1 0] [ 0 0 0 1 -1 0 1 0] [ 0 0 0 0 0 0 1 0] [ 0 -1 1 0 0 0 1 0]
>>> from sage.all import * >>> A = AffinePermutationGroup(['A',Integer(7),Integer(1)]) >>> p=A([Integer(3), -Integer(1), Integer(0), Integer(6), Integer(5), Integer(4), Integer(10), Integer(9)]) >>> p.to_weyl_group_element() [ 0 -1 0 1 0 0 1 0] [ 1 -1 0 1 0 0 1 -1] [ 1 -1 0 1 0 0 0 0] [ 0 0 0 1 0 0 0 0] [ 0 0 0 1 0 -1 1 0] [ 0 0 0 1 -1 0 1 0] [ 0 0 0 0 0 0 1 0] [ 0 -1 1 0 0 0 1 0]
- sage.combinat.affine_permutation.AffinePermutationGroup(cartan_type)[source]#
Wrapper function for specific affine permutation groups.
These are combinatorial implementations of the affine Weyl groups of types \(A\), \(B\), \(C\), \(D\), and \(G\) as permutations of the set of all integers. the basic algorithms are derived from [BB2005] and [Eri1995].
EXAMPLES:
sage: ct = CartanType(['A',7,1]) sage: A = AffinePermutationGroup(ct) sage: A The group of affine permutations of type ['A', 7, 1]
>>> from sage.all import * >>> ct = CartanType(['A',Integer(7),Integer(1)]) >>> A = AffinePermutationGroup(ct) >>> A The group of affine permutations of type ['A', 7, 1]
We define an element of
A
:sage: p = A([3, -1, 0, 6, 5, 4, 10, 9]) sage: p Type A affine permutation with window [3, -1, 0, 6, 5, 4, 10, 9]
>>> from sage.all import * >>> p = A([Integer(3), -Integer(1), Integer(0), Integer(6), Integer(5), Integer(4), Integer(10), Integer(9)]) >>> p Type A affine permutation with window [3, -1, 0, 6, 5, 4, 10, 9]
We find the value \(p(1)\), considering \(p\) as a bijection on the integers. This is the same as calling the
value()
method:sage: p.value(1) 3 sage: p(1) == p.value(1) True
>>> from sage.all import * >>> p.value(Integer(1)) 3 >>> p(Integer(1)) == p.value(Integer(1)) True
We can also find the position of the integer 3 in \(p\) considered as a sequence, equivalent to finding \(p^{-1}(3)\):
sage: p.position(3) 1 sage: (p^-1)(3) 1
>>> from sage.all import * >>> p.position(Integer(3)) 1 >>> (p**-Integer(1))(Integer(3)) 1
Since the affine permutation group is a group, we demonstrate its group properties:
sage: A.one() Type A affine permutation with window [1, 2, 3, 4, 5, 6, 7, 8] sage: q = A([0, 2, 3, 4, 5, 6, 7, 9]) sage: p * q Type A affine permutation with window [1, -1, 0, 6, 5, 4, 10, 11] sage: q * p Type A affine permutation with window [3, -1, 1, 6, 5, 4, 10, 8] sage: p^-1 Type A affine permutation with window [0, -1, 1, 6, 5, 4, 10, 11] sage: p^-1 * p == A.one() True sage: p * p^-1 == A.one() True
>>> from sage.all import * >>> A.one() Type A affine permutation with window [1, 2, 3, 4, 5, 6, 7, 8] >>> q = A([Integer(0), Integer(2), Integer(3), Integer(4), Integer(5), Integer(6), Integer(7), Integer(9)]) >>> p * q Type A affine permutation with window [1, -1, 0, 6, 5, 4, 10, 11] >>> q * p Type A affine permutation with window [3, -1, 1, 6, 5, 4, 10, 8] >>> p**-Integer(1) Type A affine permutation with window [0, -1, 1, 6, 5, 4, 10, 11] >>> p**-Integer(1) * p == A.one() True >>> p * p**-Integer(1) == A.one() True
If we decide we prefer the Weyl Group implementation of the affine Weyl group, we can easily get it:
sage: p.to_weyl_group_element() [ 0 -1 0 1 0 0 1 0] [ 1 -1 0 1 0 0 1 -1] [ 1 -1 0 1 0 0 0 0] [ 0 0 0 1 0 0 0 0] [ 0 0 0 1 0 -1 1 0] [ 0 0 0 1 -1 0 1 0] [ 0 0 0 0 0 0 1 0] [ 0 -1 1 0 0 0 1 0]
>>> from sage.all import * >>> p.to_weyl_group_element() [ 0 -1 0 1 0 0 1 0] [ 1 -1 0 1 0 0 1 -1] [ 1 -1 0 1 0 0 0 0] [ 0 0 0 1 0 0 0 0] [ 0 0 0 1 0 -1 1 0] [ 0 0 0 1 -1 0 1 0] [ 0 0 0 0 0 0 1 0] [ 0 -1 1 0 0 0 1 0]
We can find a reduced word and do all of the other things one expects in a Coxeter group:
sage: p.has_right_descent(1) True sage: p.apply_simple_reflection(1) Type A affine permutation with window [-1, 3, 0, 6, 5, 4, 10, 9] sage: p.apply_simple_reflection(0) Type A affine permutation with window [1, -1, 0, 6, 5, 4, 10, 11] sage: p.reduced_word() [0, 7, 4, 1, 0, 7, 5, 4, 2, 1] sage: p.length() 10
>>> from sage.all import * >>> p.has_right_descent(Integer(1)) True >>> p.apply_simple_reflection(Integer(1)) Type A affine permutation with window [-1, 3, 0, 6, 5, 4, 10, 9] >>> p.apply_simple_reflection(Integer(0)) Type A affine permutation with window [1, -1, 0, 6, 5, 4, 10, 11] >>> p.reduced_word() [0, 7, 4, 1, 0, 7, 5, 4, 2, 1] >>> p.length() 10
The following methods are particular to type \(A\). We can check if the element is fully commutative:
sage: p.is_fully_commutative() False sage: q.is_fully_commutative() True
>>> from sage.all import * >>> p.is_fully_commutative() False >>> q.is_fully_commutative() True
We can also compute the affine Lehmer code of the permutation, a weak composition with \(k + 1\) entries:
sage: p.to_lehmer_code() [0, 3, 3, 0, 1, 2, 0, 1]
>>> from sage.all import * >>> p.to_lehmer_code() [0, 3, 3, 0, 1, 2, 0, 1]
Once we have the Lehmer code, we can obtain a \(k\)-bounded partition by sorting the Lehmer code, and then reading the row lengths. There is a unique 0-Grassmanian (dominant) affine permutation associated to this \(k\)-bounded partition, and a \(k\)-core as well.
sage: p.to_bounded_partition() [5, 3, 2] sage: p.to_dominant() Type A affine permutation with window [-2, -1, 1, 3, 4, 8, 10, 13] sage: p.to_core() [5, 3, 2]
>>> from sage.all import * >>> p.to_bounded_partition() [5, 3, 2] >>> p.to_dominant() Type A affine permutation with window [-2, -1, 1, 3, 4, 8, 10, 13] >>> p.to_core() [5, 3, 2]
Finally, we can take a reduced word for \(p\) and insert it to find a standard composition tableau associated uniquely to that word:
sage: p.tableau_of_word(p.reduced_word()) [[], [1, 6, 9], [2, 7, 10], [], [3], [4, 8], [], [5]]
>>> from sage.all import * >>> p.tableau_of_word(p.reduced_word()) [[], [1, 6, 9], [2, 7, 10], [], [3], [4, 8], [], [5]]
We can also form affine permutation groups in types \(B\), \(C\), \(D\), and \(G\):
sage: B = AffinePermutationGroup(['B',4,1]) sage: B.an_element() Type B affine permutation with window [-1, 3, 4, 11] sage: C = AffinePermutationGroup(['C',4,1]) sage: C.an_element() Type C affine permutation with window [2, 3, 4, 10] sage: D = AffinePermutationGroup(['D',4,1]) sage: D.an_element() Type D affine permutation with window [-1, 3, 11, 5] sage: G = AffinePermutationGroup(['G',2,1]) sage: G.an_element() Type G affine permutation with window [0, 4, -1, 8, 3, 7]
>>> from sage.all import * >>> B = AffinePermutationGroup(['B',Integer(4),Integer(1)]) >>> B.an_element() Type B affine permutation with window [-1, 3, 4, 11] >>> C = AffinePermutationGroup(['C',Integer(4),Integer(1)]) >>> C.an_element() Type C affine permutation with window [2, 3, 4, 10] >>> D = AffinePermutationGroup(['D',Integer(4),Integer(1)]) >>> D.an_element() Type D affine permutation with window [-1, 3, 11, 5] >>> G = AffinePermutationGroup(['G',Integer(2),Integer(1)]) >>> G.an_element() Type G affine permutation with window [0, 4, -1, 8, 3, 7]
- class sage.combinat.affine_permutation.AffinePermutationGroupGeneric(cartan_type)[source]#
Bases:
UniqueRepresentation
,Parent
The generic affine permutation group class, in which we define all type-free methods for the specific affine permutation groups.
- cartan_matrix()[source]#
Returns the Cartan matrix of
self
.EXAMPLES:
sage: AffinePermutationGroup(['A',7,1]).cartan_matrix() [ 2 -1 0 0 0 0 0 -1] [-1 2 -1 0 0 0 0 0] [ 0 -1 2 -1 0 0 0 0] [ 0 0 -1 2 -1 0 0 0] [ 0 0 0 -1 2 -1 0 0] [ 0 0 0 0 -1 2 -1 0] [ 0 0 0 0 0 -1 2 -1] [-1 0 0 0 0 0 -1 2]
>>> from sage.all import * >>> AffinePermutationGroup(['A',Integer(7),Integer(1)]).cartan_matrix() [ 2 -1 0 0 0 0 0 -1] [-1 2 -1 0 0 0 0 0] [ 0 -1 2 -1 0 0 0 0] [ 0 0 -1 2 -1 0 0 0] [ 0 0 0 -1 2 -1 0 0] [ 0 0 0 0 -1 2 -1 0] [ 0 0 0 0 0 -1 2 -1] [-1 0 0 0 0 0 -1 2]
- cartan_type()[source]#
Returns the Cartan type of
self
.EXAMPLES:
sage: AffinePermutationGroup(['A',7,1]).cartan_type() ['A', 7, 1]
>>> from sage.all import * >>> AffinePermutationGroup(['A',Integer(7),Integer(1)]).cartan_type() ['A', 7, 1]
- classical()[source]#
Returns the finite permutation group.
EXAMPLES:
sage: A = AffinePermutationGroup(['A',7,1]) sage: A.classical() Symmetric group of order 8! as a permutation group
>>> from sage.all import * >>> A = AffinePermutationGroup(['A',Integer(7),Integer(1)]) >>> A.classical() Symmetric group of order 8! as a permutation group
- from_word(w)[source]#
Builds an affine permutation from a given word. Note: Already in category as
from_reduced_word
, but this is less typing!EXAMPLES:
sage: A = AffinePermutationGroup(['A',7,1]) sage: p=A([3, -1, 0, 6, 5, 4, 10, 9]) sage: A.from_word([0, 7, 4, 1, 0, 7, 5, 4, 2, 1]) Type A affine permutation with window [3, -1, 0, 6, 5, 4, 10, 9]
>>> from sage.all import * >>> A = AffinePermutationGroup(['A',Integer(7),Integer(1)]) >>> p=A([Integer(3), -Integer(1), Integer(0), Integer(6), Integer(5), Integer(4), Integer(10), Integer(9)]) >>> A.from_word([Integer(0), Integer(7), Integer(4), Integer(1), Integer(0), Integer(7), Integer(5), Integer(4), Integer(2), Integer(1)]) Type A affine permutation with window [3, -1, 0, 6, 5, 4, 10, 9]
- index_set()[source]#
EXAMPLES:
sage: AffinePermutationGroup(['A',7,1]).index_set() (0, 1, 2, 3, 4, 5, 6, 7)
>>> from sage.all import * >>> AffinePermutationGroup(['A',Integer(7),Integer(1)]).index_set() (0, 1, 2, 3, 4, 5, 6, 7)
- is_crystallographic()[source]#
Tells whether the affine permutation group is crystallographic.
EXAMPLES:
sage: AffinePermutationGroup(['A',7,1]).is_crystallographic() True
>>> from sage.all import * >>> AffinePermutationGroup(['A',Integer(7),Integer(1)]).is_crystallographic() True
- random_element(n=None)[source]#
Return a random affine permutation of length
n
.If
n
is not specified, thenn
is chosen as a random non-negative integer in \([0, 1000]\).Starts at the identity, then chooses an upper cover at random. Not very uniform: actually constructs a uniformly random reduced word of length \(n\). Thus we most likely get elements with lots of reduced words!
For the actual code, see
sage.categories.coxeter_group.random_element_of_length()
.EXAMPLES:
sage: A = AffinePermutationGroup(['A',7,1]) sage: A.random_element() # random Type A affine permutation with window [-12, 16, 19, -1, -2, 10, -3, 9] sage: p = A.random_element(10) sage: p.length() == 10 True
>>> from sage.all import * >>> A = AffinePermutationGroup(['A',Integer(7),Integer(1)]) >>> A.random_element() # random Type A affine permutation with window [-12, 16, 19, -1, -2, 10, -3, 9] >>> p = A.random_element(Integer(10)) >>> p.length() == Integer(10) True
- rank()[source]#
Rank of the affine permutation group, equal to \(k+1\).
EXAMPLES:
sage: AffinePermutationGroup(['A',7,1]).rank() 8
>>> from sage.all import * >>> AffinePermutationGroup(['A',Integer(7),Integer(1)]).rank() 8
- reflection_index_set()[source]#
EXAMPLES:
sage: AffinePermutationGroup(['A',7,1]).reflection_index_set() (0, 1, 2, 3, 4, 5, 6, 7)
>>> from sage.all import * >>> AffinePermutationGroup(['A',Integer(7),Integer(1)]).reflection_index_set() (0, 1, 2, 3, 4, 5, 6, 7)
- weyl_group()[source]#
Returns the Weyl Group of the same type as
self
.EXAMPLES:
sage: A = AffinePermutationGroup(['A',7,1]) sage: A.weyl_group() Weyl Group of type ['A', 7, 1] (as a matrix group acting on the root space)
>>> from sage.all import * >>> A = AffinePermutationGroup(['A',Integer(7),Integer(1)]) >>> A.weyl_group() Weyl Group of type ['A', 7, 1] (as a matrix group acting on the root space)
- class sage.combinat.affine_permutation.AffinePermutationGroupTypeA(cartan_type)[source]#
Bases:
AffinePermutationGroupGeneric
- Element[source]#
alias of
AffinePermutationTypeA
- from_lehmer_code(C, typ='decreasing', side='right')[source]#
Return the affine permutation with the supplied Lehmer code (a weak composition with \(k+1\) parts, at least one of which is 0).
INPUT:
typ
–'increasing'
or'decreasing'
(default:'decreasing'
); type of productside
–'right'
or'left'
(default:'right'
); whether the decomposition is from the right or left
EXAMPLES:
sage: import itertools sage: A = AffinePermutationGroup(['A',7,1]) sage: p = A([3, -1, 0, 6, 5, 4, 10, 9]) sage: p.to_lehmer_code() [0, 3, 3, 0, 1, 2, 0, 1] sage: A.from_lehmer_code(p.to_lehmer_code()) == p True sage: orders = ('increasing','decreasing') sage: sides = ('left','right') sage: all(A.from_lehmer_code(p.to_lehmer_code(o,s),o,s) == p ....: for o,s in itertools.product(orders,sides)) True
>>> from sage.all import * >>> import itertools >>> A = AffinePermutationGroup(['A',Integer(7),Integer(1)]) >>> p = A([Integer(3), -Integer(1), Integer(0), Integer(6), Integer(5), Integer(4), Integer(10), Integer(9)]) >>> p.to_lehmer_code() [0, 3, 3, 0, 1, 2, 0, 1] >>> A.from_lehmer_code(p.to_lehmer_code()) == p True >>> orders = ('increasing','decreasing') >>> sides = ('left','right') >>> all(A.from_lehmer_code(p.to_lehmer_code(o,s),o,s) == p ... for o,s in itertools.product(orders,sides)) True
- one()[source]#
Return the identity element.
EXAMPLES:
sage: AffinePermutationGroup(['A',7,1]).one() Type A affine permutation with window [1, 2, 3, 4, 5, 6, 7, 8]
>>> from sage.all import * >>> AffinePermutationGroup(['A',Integer(7),Integer(1)]).one() Type A affine permutation with window [1, 2, 3, 4, 5, 6, 7, 8]
- class sage.combinat.affine_permutation.AffinePermutationGroupTypeB(cartan_type)[source]#
Bases:
AffinePermutationGroupTypeC
- Element[source]#
alias of
AffinePermutationTypeB
- class sage.combinat.affine_permutation.AffinePermutationGroupTypeC(cartan_type)[source]#
Bases:
AffinePermutationGroupGeneric
- Element[source]#
alias of
AffinePermutationTypeC
- one()[source]#
Return the identity element.
EXAMPLES:
sage: ct=CartanType(['C',4,1]) sage: C = AffinePermutationGroup(ct) sage: C.one() Type C affine permutation with window [1, 2, 3, 4] sage: C.one()*C.one()==C.one() True
>>> from sage.all import * >>> ct=CartanType(['C',Integer(4),Integer(1)]) >>> C = AffinePermutationGroup(ct) >>> C.one() Type C affine permutation with window [1, 2, 3, 4] >>> C.one()*C.one()==C.one() True
- class sage.combinat.affine_permutation.AffinePermutationGroupTypeD(cartan_type)[source]#
Bases:
AffinePermutationGroupTypeC
- Element[source]#
alias of
AffinePermutationTypeD
- class sage.combinat.affine_permutation.AffinePermutationGroupTypeG(cartan_type)[source]#
Bases:
AffinePermutationGroupGeneric
- Element[source]#
alias of
AffinePermutationTypeG
- one()[source]#
Return the identity element.
EXAMPLES:
sage: AffinePermutationGroup(['G',2,1]).one() Type G affine permutation with window [1, 2, 3, 4, 5, 6]
>>> from sage.all import * >>> AffinePermutationGroup(['G',Integer(2),Integer(1)]).one() Type G affine permutation with window [1, 2, 3, 4, 5, 6]
- class sage.combinat.affine_permutation.AffinePermutationTypeA(parent, lst, check=True)[source]#
Bases:
AffinePermutation
- apply_simple_reflection_left(i)[source]#
Apply the simple reflection to the values \(i\), \(i+1\).
EXAMPLES:
sage: p = AffinePermutationGroup(['A',7,1])([3, -1, 0, 6, 5, 4, 10, 9]) sage: p.apply_simple_reflection_left(3) Type A affine permutation with window [4, -1, 0, 6, 5, 3, 10, 9] sage: p.apply_simple_reflection_left(11) Type A affine permutation with window [4, -1, 0, 6, 5, 3, 10, 9]
>>> from sage.all import * >>> p = AffinePermutationGroup(['A',Integer(7),Integer(1)])([Integer(3), -Integer(1), Integer(0), Integer(6), Integer(5), Integer(4), Integer(10), Integer(9)]) >>> p.apply_simple_reflection_left(Integer(3)) Type A affine permutation with window [4, -1, 0, 6, 5, 3, 10, 9] >>> p.apply_simple_reflection_left(Integer(11)) Type A affine permutation with window [4, -1, 0, 6, 5, 3, 10, 9]
- apply_simple_reflection_right(i)[source]#
Apply the simple reflection to positions \(i\), \(i+1\).
INPUT:
i
– an integer
EXAMPLES:
sage: p = AffinePermutationGroup(['A',7,1])([3, -1, 0, 6, 5, 4, 10, 9]) sage: p.apply_simple_reflection_right(3) Type A affine permutation with window [3, -1, 6, 0, 5, 4, 10, 9] sage: p.apply_simple_reflection_right(11) Type A affine permutation with window [3, -1, 6, 0, 5, 4, 10, 9]
>>> from sage.all import * >>> p = AffinePermutationGroup(['A',Integer(7),Integer(1)])([Integer(3), -Integer(1), Integer(0), Integer(6), Integer(5), Integer(4), Integer(10), Integer(9)]) >>> p.apply_simple_reflection_right(Integer(3)) Type A affine permutation with window [3, -1, 6, 0, 5, 4, 10, 9] >>> p.apply_simple_reflection_right(Integer(11)) Type A affine permutation with window [3, -1, 6, 0, 5, 4, 10, 9]
- check()[source]#
Check that
self
is an affine permutation.EXAMPLES:
sage: A = AffinePermutationGroup(['A',7,1]) sage: p = A([3, -1, 0, 6, 5, 4, 10, 9]) sage: p Type A affine permutation with window [3, -1, 0, 6, 5, 4, 10, 9] sage: q = A([1,2,3]) # indirect doctest Traceback (most recent call last): ... ValueError: length of list must be k+1=8 sage: q = A([1,2,3,4,5,6,7,0]) # indirect doctest Traceback (most recent call last): ... ValueError: window does not sum to 36 sage: q = A([1,1,3,4,5,6,7,9]) # indirect doctest Traceback (most recent call last): ... ValueError: entries must have distinct residues
>>> from sage.all import * >>> A = AffinePermutationGroup(['A',Integer(7),Integer(1)]) >>> p = A([Integer(3), -Integer(1), Integer(0), Integer(6), Integer(5), Integer(4), Integer(10), Integer(9)]) >>> p Type A affine permutation with window [3, -1, 0, 6, 5, 4, 10, 9] >>> q = A([Integer(1),Integer(2),Integer(3)]) # indirect doctest Traceback (most recent call last): ... ValueError: length of list must be k+1=8 >>> q = A([Integer(1),Integer(2),Integer(3),Integer(4),Integer(5),Integer(6),Integer(7),Integer(0)]) # indirect doctest Traceback (most recent call last): ... ValueError: window does not sum to 36 >>> q = A([Integer(1),Integer(1),Integer(3),Integer(4),Integer(5),Integer(6),Integer(7),Integer(9)]) # indirect doctest Traceback (most recent call last): ... ValueError: entries must have distinct residues
- flip_automorphism()[source]#
The Dynkin diagram automorphism which fixes \(s_0\) and reverses all other indices.
EXAMPLES:
sage: A = AffinePermutationGroup(['A',7,1]) sage: p=A([3, -1, 0, 6, 5, 4, 10, 9]) sage: p.flip_automorphism() Type A affine permutation with window [0, -1, 5, 4, 3, 9, 10, 6]
>>> from sage.all import * >>> A = AffinePermutationGroup(['A',Integer(7),Integer(1)]) >>> p=A([Integer(3), -Integer(1), Integer(0), Integer(6), Integer(5), Integer(4), Integer(10), Integer(9)]) >>> p.flip_automorphism() Type A affine permutation with window [0, -1, 5, 4, 3, 9, 10, 6]
- has_left_descent(i)[source]#
Determine whether there is a descent at
i
.INPUT:
i
– an integer
EXAMPLES:
sage: p = AffinePermutationGroup(['A',7,1])([3, -1, 0, 6, 5, 4, 10, 9]) sage: p.has_left_descent(1) True sage: p.has_left_descent(9) True sage: p.has_left_descent(0) True
>>> from sage.all import * >>> p = AffinePermutationGroup(['A',Integer(7),Integer(1)])([Integer(3), -Integer(1), Integer(0), Integer(6), Integer(5), Integer(4), Integer(10), Integer(9)]) >>> p.has_left_descent(Integer(1)) True >>> p.has_left_descent(Integer(9)) True >>> p.has_left_descent(Integer(0)) True
- has_right_descent(i)[source]#
Determine whether there is a descent at
i
.INPUT:
i
– an integer
EXAMPLES:
sage: p = AffinePermutationGroup(['A',7,1])([3, -1, 0, 6, 5, 4, 10, 9]) sage: p.has_right_descent(1) True sage: p.has_right_descent(9) True sage: p.has_right_descent(0) False
>>> from sage.all import * >>> p = AffinePermutationGroup(['A',Integer(7),Integer(1)])([Integer(3), -Integer(1), Integer(0), Integer(6), Integer(5), Integer(4), Integer(10), Integer(9)]) >>> p.has_right_descent(Integer(1)) True >>> p.has_right_descent(Integer(9)) True >>> p.has_right_descent(Integer(0)) False
- is_fully_commutative()[source]#
Determine whether
self
is fully commutative.This means that it has no reduced word with a braid.
This uses a specific algorithm.
EXAMPLES:
sage: A = AffinePermutationGroup(['A',7,1]) sage: p = A([3, -1, 0, 6, 5, 4, 10, 9]) sage: p.is_fully_commutative() False sage: q = A([-3, -2, 0, 7, 9, 2, 11, 12]) sage: q.is_fully_commutative() True
>>> from sage.all import * >>> A = AffinePermutationGroup(['A',Integer(7),Integer(1)]) >>> p = A([Integer(3), -Integer(1), Integer(0), Integer(6), Integer(5), Integer(4), Integer(10), Integer(9)]) >>> p.is_fully_commutative() False >>> q = A([-Integer(3), -Integer(2), Integer(0), Integer(7), Integer(9), Integer(2), Integer(11), Integer(12)]) >>> q.is_fully_commutative() True
- maximal_cyclic_decomposition(typ='decreasing', side='right', verbose=False)[source]#
Find the unique maximal decomposition of
self
into cyclically decreasing/increasing elements.INPUT:
typ
–'increasing'
or'decreasing'
(default:'decreasing'
); chooses whether to find increasing or decreasing setsside
–'right'
or'left'
(default:'right'
) chooses whether to find maximal sets starting from the left or the rightverbose
– (default:False
) print extra information while finding the decomposition
EXAMPLES:
sage: p = AffinePermutationGroup(['A',7,1])([3, -1, 0, 6, 5, 4, 10, 9]) sage: p.maximal_cyclic_decomposition() [[0, 7], [4, 1, 0], [7, 5, 4, 2, 1]] sage: p.maximal_cyclic_decomposition(side='left') [[1, 0, 7, 5, 4], [1, 0, 5], [2, 1]] sage: p.maximal_cyclic_decomposition(typ='increasing', side='right') [[1], [5, 0, 1, 2], [4, 5, 7, 0, 1]] sage: p.maximal_cyclic_decomposition(typ='increasing', side='left') [[0, 1, 2, 4, 5], [4, 7, 0, 1], [7]]
>>> from sage.all import * >>> p = AffinePermutationGroup(['A',Integer(7),Integer(1)])([Integer(3), -Integer(1), Integer(0), Integer(6), Integer(5), Integer(4), Integer(10), Integer(9)]) >>> p.maximal_cyclic_decomposition() [[0, 7], [4, 1, 0], [7, 5, 4, 2, 1]] >>> p.maximal_cyclic_decomposition(side='left') [[1, 0, 7, 5, 4], [1, 0, 5], [2, 1]] >>> p.maximal_cyclic_decomposition(typ='increasing', side='right') [[1], [5, 0, 1, 2], [4, 5, 7, 0, 1]] >>> p.maximal_cyclic_decomposition(typ='increasing', side='left') [[0, 1, 2, 4, 5], [4, 7, 0, 1], [7]]
- maximal_cyclic_factor(typ='decreasing', side='right', verbose=False)[source]#
For an affine permutation \(x\), find the unique maximal subset \(A\) of the index set such that \(x = yd_A\) is a reduced product.
INPUT:
typ
–'increasing'
or'decreasing'
(default:'decreasing'
); chooses whether to find increasing or decreasing setsside
–'right'
or'left'
(default:'right'
) chooses whether to find maximal sets starting from the left or the rightverbose
– True or False. If True, outputs information about how the cyclically increasing element was found.
EXAMPLES:
sage: p = AffinePermutationGroup(['A',7,1])([3, -1, 0, 6, 5, 4, 10, 9]) sage: p.maximal_cyclic_factor() [7, 5, 4, 2, 1] sage: p.maximal_cyclic_factor(side='left') [1, 0, 7, 5, 4] sage: p.maximal_cyclic_factor('increasing','right') [4, 5, 7, 0, 1] sage: p.maximal_cyclic_factor('increasing','left') [0, 1, 2, 4, 5]
>>> from sage.all import * >>> p = AffinePermutationGroup(['A',Integer(7),Integer(1)])([Integer(3), -Integer(1), Integer(0), Integer(6), Integer(5), Integer(4), Integer(10), Integer(9)]) >>> p.maximal_cyclic_factor() [7, 5, 4, 2, 1] >>> p.maximal_cyclic_factor(side='left') [1, 0, 7, 5, 4] >>> p.maximal_cyclic_factor('increasing','right') [4, 5, 7, 0, 1] >>> p.maximal_cyclic_factor('increasing','left') [0, 1, 2, 4, 5]
- position(i)[source]#
Find the position
j
such theself.value(j) == i
.EXAMPLES:
sage: A = AffinePermutationGroup(['A',7,1]) sage: p = A([3, -1, 0, 6, 5, 4, 10, 9]) sage: p.position(3) 1 sage: p.position(11) 9
>>> from sage.all import * >>> A = AffinePermutationGroup(['A',Integer(7),Integer(1)]) >>> p = A([Integer(3), -Integer(1), Integer(0), Integer(6), Integer(5), Integer(4), Integer(10), Integer(9)]) >>> p.position(Integer(3)) 1 >>> p.position(Integer(11)) 9
- promotion()[source]#
The Dynkin diagram automorphism which sends \(s_i\) to \(s_{i+1}\).
EXAMPLES:
sage: A = AffinePermutationGroup(['A',7,1]) sage: p = A([3, -1, 0, 6, 5, 4, 10, 9]) sage: p.promotion() Type A affine permutation with window [2, 4, 0, 1, 7, 6, 5, 11]
>>> from sage.all import * >>> A = AffinePermutationGroup(['A',Integer(7),Integer(1)]) >>> p = A([Integer(3), -Integer(1), Integer(0), Integer(6), Integer(5), Integer(4), Integer(10), Integer(9)]) >>> p.promotion() Type A affine permutation with window [2, 4, 0, 1, 7, 6, 5, 11]
- tableau_of_word(w, typ='decreasing', side='right', alpha=None)[source]#
Finds a tableau on the Lehmer code of
self
corresponding to the given reduced word.For a full description of this algorithm, see [Den2012].
INPUT:
w
– a reduced word forself
typ
–'increasing'
or'decreasing'
; the type of Lehmer code usedside
–'right'
or'left'
alpha
– a content vector;w
should be of typealpha
; specifyingalpha
produces semistandard tableaux
EXAMPLES:
sage: A = AffinePermutationGroup(['A',7,1]) sage: p=A([3, -1, 0, 6, 5, 4, 10, 9]) sage: p.tableau_of_word(p.reduced_word()) [[], [1, 6, 9], [2, 7, 10], [], [3], [4, 8], [], [5]] sage: A = AffinePermutationGroup(['A',7,1]) sage: p=A([3, -1, 0, 6, 5, 4, 10, 9]) sage: w=p.reduced_word() sage: w [0, 7, 4, 1, 0, 7, 5, 4, 2, 1] sage: alpha=[5,3,2] sage: p.tableau_of_word(p.reduced_word(), alpha=alpha) [[], [1, 2, 3], [1, 2, 3], [], [1], [1, 2], [], [1]] sage: p.tableau_of_word(p.reduced_word(), side='left') [[1, 4, 9], [6], [], [], [3, 7], [8], [], [2, 5, 10]] sage: p.tableau_of_word(p.reduced_word(), typ='increasing', side='right') [[9, 10], [1, 2], [], [], [3, 4], [8], [], [5, 6, 7]] sage: p.tableau_of_word(p.reduced_word(), typ='increasing', side='left') [[1, 2], [4, 5, 6], [9, 10], [], [3], [7, 8], [], []]
>>> from sage.all import * >>> A = AffinePermutationGroup(['A',Integer(7),Integer(1)]) >>> p=A([Integer(3), -Integer(1), Integer(0), Integer(6), Integer(5), Integer(4), Integer(10), Integer(9)]) >>> p.tableau_of_word(p.reduced_word()) [[], [1, 6, 9], [2, 7, 10], [], [3], [4, 8], [], [5]] >>> A = AffinePermutationGroup(['A',Integer(7),Integer(1)]) >>> p=A([Integer(3), -Integer(1), Integer(0), Integer(6), Integer(5), Integer(4), Integer(10), Integer(9)]) >>> w=p.reduced_word() >>> w [0, 7, 4, 1, 0, 7, 5, 4, 2, 1] >>> alpha=[Integer(5),Integer(3),Integer(2)] >>> p.tableau_of_word(p.reduced_word(), alpha=alpha) [[], [1, 2, 3], [1, 2, 3], [], [1], [1, 2], [], [1]] >>> p.tableau_of_word(p.reduced_word(), side='left') [[1, 4, 9], [6], [], [], [3, 7], [8], [], [2, 5, 10]] >>> p.tableau_of_word(p.reduced_word(), typ='increasing', side='right') [[9, 10], [1, 2], [], [], [3, 4], [8], [], [5, 6, 7]] >>> p.tableau_of_word(p.reduced_word(), typ='increasing', side='left') [[1, 2], [4, 5, 6], [9, 10], [], [3], [7, 8], [], []]
- to_bounded_partition(typ='decreasing', side='right')[source]#
Return the \(k\)-bounded partition associated to the dominant element obtained by sorting the Lehmer code.
INPUT:
typ
–'increasing'
or'decreasing'
(default:'decreasing'
.) Chooses whether to find increasing or decreasing sets.side
–'right'
or'left'
(default:'right'
.) Chooses whether to find maximal sets starting from the left or the right.
EXAMPLES:
sage: A = AffinePermutationGroup(['A',2,1]) sage: p=A.from_lehmer_code([4,1,0]) sage: p.to_bounded_partition() [2, 1, 1, 1]
>>> from sage.all import * >>> A = AffinePermutationGroup(['A',Integer(2),Integer(1)]) >>> p=A.from_lehmer_code([Integer(4),Integer(1),Integer(0)]) >>> p.to_bounded_partition() [2, 1, 1, 1]
- to_core(typ='decreasing', side='right')[source]#
Returns the core associated to the dominant element obtained by sorting the Lehmer code.
INPUT:
typ
–'increasing'
or'decreasing'
(default:'decreasing'
.)side
–'right'
or'left'
(default:'right'
.) Chooses whether to find maximal sets starting from the left or the right.
EXAMPLES:
sage: A = AffinePermutationGroup(['A',2,1]) sage: p=A.from_lehmer_code([4,1,0]) sage: p.to_bounded_partition() [2, 1, 1, 1] sage: p.to_core() [4, 2, 1, 1]
>>> from sage.all import * >>> A = AffinePermutationGroup(['A',Integer(2),Integer(1)]) >>> p=A.from_lehmer_code([Integer(4),Integer(1),Integer(0)]) >>> p.to_bounded_partition() [2, 1, 1, 1] >>> p.to_core() [4, 2, 1, 1]
- to_dominant(typ='decreasing', side='right')[source]#
Finds the Lehmer code and then sorts it. Returns the affine permutation with the given sorted Lehmer code; this element is 0-dominant.
INPUT:
typ
–'increasing'
or'decreasing'
(default:'decreasing'
) chooses whether to find increasing or decreasing setsside
–'right'
or'left'
(default:'right'
) chooses whether to find maximal sets starting from the left or the right
EXAMPLES:
sage: A = AffinePermutationGroup(['A',7,1]) sage: p=A([3, -1, 0, 6, 5, 4, 10, 9]) sage: p.to_dominant() Type A affine permutation with window [-2, -1, 1, 3, 4, 8, 10, 13] sage: p.to_dominant(typ='increasing', side='left') Type A affine permutation with window [3, 4, -1, 5, 0, 9, 6, 10]
>>> from sage.all import * >>> A = AffinePermutationGroup(['A',Integer(7),Integer(1)]) >>> p=A([Integer(3), -Integer(1), Integer(0), Integer(6), Integer(5), Integer(4), Integer(10), Integer(9)]) >>> p.to_dominant() Type A affine permutation with window [-2, -1, 1, 3, 4, 8, 10, 13] >>> p.to_dominant(typ='increasing', side='left') Type A affine permutation with window [3, 4, -1, 5, 0, 9, 6, 10]
- to_lehmer_code(typ='decreasing', side='right')[source]#
Return the affine Lehmer code.
There are four such codes; the options
typ
andside
determine which code is generated. The codes generated are the shape of the maximal cyclic decompositions ofself
according to the giventyp
andside
options.INPUT:
typ
–'increasing'
or'decreasing'
(default:'decreasing'
); chooses whether to find increasing or decreasing setsside
–'right'
or'left'
(default:'right'
) chooses whether to find maximal sets starting from the left or the right
EXAMPLES:
sage: import itertools sage: A = AffinePermutationGroup(['A',7,1]) sage: p=A([3, -1, 0, 6, 5, 4, 10, 9]) sage: orders = ('increasing','decreasing') sage: sides = ('left','right') sage: for o,s in itertools.product(orders, sides): ....: p.to_lehmer_code(o,s) [2, 3, 2, 0, 1, 2, 0, 0] [2, 2, 0, 0, 2, 1, 0, 3] [3, 1, 0, 0, 2, 1, 0, 3] [0, 3, 3, 0, 1, 2, 0, 1] sage: for a in itertools.product(orders, sides): ....: A.from_lehmer_code(p.to_lehmer_code(a[0],a[1]), a[0],a[1])==p True True True True
>>> from sage.all import * >>> import itertools >>> A = AffinePermutationGroup(['A',Integer(7),Integer(1)]) >>> p=A([Integer(3), -Integer(1), Integer(0), Integer(6), Integer(5), Integer(4), Integer(10), Integer(9)]) >>> orders = ('increasing','decreasing') >>> sides = ('left','right') >>> for o,s in itertools.product(orders, sides): ... p.to_lehmer_code(o,s) [2, 3, 2, 0, 1, 2, 0, 0] [2, 2, 0, 0, 2, 1, 0, 3] [3, 1, 0, 0, 2, 1, 0, 3] [0, 3, 3, 0, 1, 2, 0, 1] >>> for a in itertools.product(orders, sides): ... A.from_lehmer_code(p.to_lehmer_code(a[Integer(0)],a[Integer(1)]), a[Integer(0)],a[Integer(1)])==p True True True True
- to_type_a()[source]#
Return an embedding of
self
into the affine permutation group of type \(A\). (For type \(A\), just returnsself
.)EXAMPLES:
sage: p = AffinePermutationGroup(['A',7,1])([3, -1, 0, 6, 5, 4, 10, 9]) sage: p.to_type_a() is p True
>>> from sage.all import * >>> p = AffinePermutationGroup(['A',Integer(7),Integer(1)])([Integer(3), -Integer(1), Integer(0), Integer(6), Integer(5), Integer(4), Integer(10), Integer(9)]) >>> p.to_type_a() is p True
- value(i, base_window=False)[source]#
Return the image of the integer
i
under this permutation.INPUT:
base_window
– boolean; indicating whetheri
is in the base window; ifTrue
, will run a bit faster, but the method will screw up ifi
is not actually in the index set
EXAMPLES:
sage: A = AffinePermutationGroup(['A',7,1]) sage: p = A([3, -1, 0, 6, 5, 4, 10, 9]) sage: p.value(1) 3 sage: p.value(9) 11
>>> from sage.all import * >>> A = AffinePermutationGroup(['A',Integer(7),Integer(1)]) >>> p = A([Integer(3), -Integer(1), Integer(0), Integer(6), Integer(5), Integer(4), Integer(10), Integer(9)]) >>> p.value(Integer(1)) 3 >>> p.value(Integer(9)) 11
- class sage.combinat.affine_permutation.AffinePermutationTypeB(parent, lst, check=True)[source]#
Bases:
AffinePermutationTypeC
- apply_simple_reflection_left(i)[source]#
Apply the simple reflection indexed by
i
on values.EXAMPLES:
sage: B = AffinePermutationGroup(['B',4,1]) sage: p=B([-5,1,6,-2]) sage: p.apply_simple_reflection_left(0) Type B affine permutation with window [-5, -2, 6, 1] sage: p.apply_simple_reflection_left(2) Type B affine permutation with window [-5, 1, 7, -3] sage: p.apply_simple_reflection_left(4) Type B affine permutation with window [-4, 1, 6, -2]
>>> from sage.all import * >>> B = AffinePermutationGroup(['B',Integer(4),Integer(1)]) >>> p=B([-Integer(5),Integer(1),Integer(6),-Integer(2)]) >>> p.apply_simple_reflection_left(Integer(0)) Type B affine permutation with window [-5, -2, 6, 1] >>> p.apply_simple_reflection_left(Integer(2)) Type B affine permutation with window [-5, 1, 7, -3] >>> p.apply_simple_reflection_left(Integer(4)) Type B affine permutation with window [-4, 1, 6, -2]
- apply_simple_reflection_right(i)[source]#
Apply the simple reflection indexed by
i
on positions.EXAMPLES:
sage: B = AffinePermutationGroup(['B',4,1]) sage: p=B([-5,1,6,-2]) sage: p.apply_simple_reflection_right(1) Type B affine permutation with window [1, -5, 6, -2] sage: p.apply_simple_reflection_right(0) Type B affine permutation with window [-1, 5, 6, -2] sage: p.apply_simple_reflection_right(4) Type B affine permutation with window [-5, 1, 6, 11]
>>> from sage.all import * >>> B = AffinePermutationGroup(['B',Integer(4),Integer(1)]) >>> p=B([-Integer(5),Integer(1),Integer(6),-Integer(2)]) >>> p.apply_simple_reflection_right(Integer(1)) Type B affine permutation with window [1, -5, 6, -2] >>> p.apply_simple_reflection_right(Integer(0)) Type B affine permutation with window [-1, 5, 6, -2] >>> p.apply_simple_reflection_right(Integer(4)) Type B affine permutation with window [-5, 1, 6, 11]
- check()[source]#
Check that
self
is an affine permutation.EXAMPLES:
sage: B = AffinePermutationGroup(['B',4,1]) sage: x = B([-5,1,6,-2]) sage: x Type B affine permutation with window [-5, 1, 6, -2]
>>> from sage.all import * >>> B = AffinePermutationGroup(['B',Integer(4),Integer(1)]) >>> x = B([-Integer(5),Integer(1),Integer(6),-Integer(2)]) >>> x Type B affine permutation with window [-5, 1, 6, -2]
- has_left_descent(i)[source]#
Determines whether there is a descent at
i
.INPUT:
i
– an integer
EXAMPLES:
sage: B = AffinePermutationGroup(['B',4,1]) sage: p=B([-5,1,6,-2]) sage: [p.has_left_descent(i) for i in B.index_set()] [True, True, False, False, True]
>>> from sage.all import * >>> B = AffinePermutationGroup(['B',Integer(4),Integer(1)]) >>> p=B([-Integer(5),Integer(1),Integer(6),-Integer(2)]) >>> [p.has_left_descent(i) for i in B.index_set()] [True, True, False, False, True]
- has_right_descent(i)[source]#
Determines whether there is a descent at index
i
.INPUT:
i
– an integer
EXAMPLES:
sage: B = AffinePermutationGroup(['B',4,1]) sage: p = B([-5,1,6,-2]) sage: [p.has_right_descent(i) for i in B.index_set()] [True, False, False, True, False]
>>> from sage.all import * >>> B = AffinePermutationGroup(['B',Integer(4),Integer(1)]) >>> p = B([-Integer(5),Integer(1),Integer(6),-Integer(2)]) >>> [p.has_right_descent(i) for i in B.index_set()] [True, False, False, True, False]
- class sage.combinat.affine_permutation.AffinePermutationTypeC(parent, lst, check=True)[source]#
Bases:
AffinePermutation
- apply_simple_reflection_left(i)[source]#
Apply the simple reflection indexed by
i
on values.EXAMPLES:
sage: C = AffinePermutationGroup(['C',4,1]) sage: x = C([-1,5,3,7]) sage: for i in C.index_set(): x.apply_simple_reflection_left(i) Type C affine permutation with window [1, 5, 3, 7] Type C affine permutation with window [-2, 5, 3, 8] Type C affine permutation with window [-1, 5, 2, 6] Type C affine permutation with window [-1, 6, 4, 7] Type C affine permutation with window [-1, 4, 3, 7]
>>> from sage.all import * >>> C = AffinePermutationGroup(['C',Integer(4),Integer(1)]) >>> x = C([-Integer(1),Integer(5),Integer(3),Integer(7)]) >>> for i in C.index_set(): x.apply_simple_reflection_left(i) Type C affine permutation with window [1, 5, 3, 7] Type C affine permutation with window [-2, 5, 3, 8] Type C affine permutation with window [-1, 5, 2, 6] Type C affine permutation with window [-1, 6, 4, 7] Type C affine permutation with window [-1, 4, 3, 7]
- apply_simple_reflection_right(i)[source]#
Apply the simple reflection indexed by
i
on positions.EXAMPLES:
sage: C = AffinePermutationGroup(['C',4,1]) sage: x=C([-1,5,3,7]) sage: for i in C.index_set(): x.apply_simple_reflection_right(i) Type C affine permutation with window [1, 5, 3, 7] Type C affine permutation with window [5, -1, 3, 7] Type C affine permutation with window [-1, 3, 5, 7] Type C affine permutation with window [-1, 5, 7, 3] Type C affine permutation with window [-1, 5, 3, 2]
>>> from sage.all import * >>> C = AffinePermutationGroup(['C',Integer(4),Integer(1)]) >>> x=C([-Integer(1),Integer(5),Integer(3),Integer(7)]) >>> for i in C.index_set(): x.apply_simple_reflection_right(i) Type C affine permutation with window [1, 5, 3, 7] Type C affine permutation with window [5, -1, 3, 7] Type C affine permutation with window [-1, 3, 5, 7] Type C affine permutation with window [-1, 5, 7, 3] Type C affine permutation with window [-1, 5, 3, 2]
- check()[source]#
Check that
self
is an affine permutation.EXAMPLES:
sage: C = AffinePermutationGroup(['C',4,1]) sage: x = C([-1,5,3,7]) sage: x Type C affine permutation with window [-1, 5, 3, 7]
>>> from sage.all import * >>> C = AffinePermutationGroup(['C',Integer(4),Integer(1)]) >>> x = C([-Integer(1),Integer(5),Integer(3),Integer(7)]) >>> x Type C affine permutation with window [-1, 5, 3, 7]
- has_left_descent(i)[source]#
Determine whether there is a descent at
i
.INPUT:
i
– an integer
EXAMPLES:
sage: C = AffinePermutationGroup(['C',4,1]) sage: x = C([-1,5,3,7]) sage: for i in C.index_set(): x.has_left_descent(i) True False True False True
>>> from sage.all import * >>> C = AffinePermutationGroup(['C',Integer(4),Integer(1)]) >>> x = C([-Integer(1),Integer(5),Integer(3),Integer(7)]) >>> for i in C.index_set(): x.has_left_descent(i) True False True False True
- has_right_descent(i)[source]#
Determine whether there is a descent at index
i
.INPUT:
i
– an integer
EXAMPLES:
sage: C = AffinePermutationGroup(['C',4,1]) sage: x = C([-1,5,3,7]) sage: for i in C.index_set(): x.has_right_descent(i) True False True False True
>>> from sage.all import * >>> C = AffinePermutationGroup(['C',Integer(4),Integer(1)]) >>> x = C([-Integer(1),Integer(5),Integer(3),Integer(7)]) >>> for i in C.index_set(): x.has_right_descent(i) True False True False True
- position(i)[source]#
Find the position \(j\) such the
self.value(j)=i
EXAMPLES:
sage: C = AffinePermutationGroup(['C',4,1]) sage: x = C.one() sage: [x.position(i) for i in range(-10,10)] == list(range(-10,10)) True
>>> from sage.all import * >>> C = AffinePermutationGroup(['C',Integer(4),Integer(1)]) >>> x = C.one() >>> [x.position(i) for i in range(-Integer(10),Integer(10))] == list(range(-Integer(10),Integer(10))) True
- to_type_a()[source]#
Return an embedding of
self
into the affine permutation group of type \(A\).EXAMPLES:
sage: C = AffinePermutationGroup(['C',4,1]) sage: x = C([-1,5,3,7]) sage: x.to_type_a() Type A affine permutation with window [-1, 5, 3, 7, 2, 6, 4, 10, 9]
>>> from sage.all import * >>> C = AffinePermutationGroup(['C',Integer(4),Integer(1)]) >>> x = C([-Integer(1),Integer(5),Integer(3),Integer(7)]) >>> x.to_type_a() Type A affine permutation with window [-1, 5, 3, 7, 2, 6, 4, 10, 9]
- value(i)[source]#
Return the image of the integer
i
under this permutation.EXAMPLES:
sage: C = AffinePermutationGroup(['C',4,1]) sage: x = C.one() sage: [x.value(i) for i in range(-10,10)] == list(range(-10,10)) True
>>> from sage.all import * >>> C = AffinePermutationGroup(['C',Integer(4),Integer(1)]) >>> x = C.one() >>> [x.value(i) for i in range(-Integer(10),Integer(10))] == list(range(-Integer(10),Integer(10))) True
- class sage.combinat.affine_permutation.AffinePermutationTypeD(parent, lst, check=True)[source]#
Bases:
AffinePermutationTypeC
- apply_simple_reflection_left(i)[source]#
Apply simple reflection indexed by
i
on values.EXAMPLES:
sage: D = AffinePermutationGroup(['D',4,1]) sage: p=D([1,-6,5,-2]) sage: p.apply_simple_reflection_left(0) Type D affine permutation with window [-2, -6, 5, 1] sage: p.apply_simple_reflection_left(1) Type D affine permutation with window [2, -6, 5, -1] sage: p.apply_simple_reflection_left(4) Type D affine permutation with window [1, -4, 3, -2]
>>> from sage.all import * >>> D = AffinePermutationGroup(['D',Integer(4),Integer(1)]) >>> p=D([Integer(1),-Integer(6),Integer(5),-Integer(2)]) >>> p.apply_simple_reflection_left(Integer(0)) Type D affine permutation with window [-2, -6, 5, 1] >>> p.apply_simple_reflection_left(Integer(1)) Type D affine permutation with window [2, -6, 5, -1] >>> p.apply_simple_reflection_left(Integer(4)) Type D affine permutation with window [1, -4, 3, -2]
- apply_simple_reflection_right(i)[source]#
Apply the simple reflection indexed by
i
on positions.EXAMPLES:
sage: D = AffinePermutationGroup(['D',4,1]) sage: p=D([1,-6,5,-2]) sage: p.apply_simple_reflection_right(0) Type D affine permutation with window [6, -1, 5, -2] sage: p.apply_simple_reflection_right(1) Type D affine permutation with window [-6, 1, 5, -2] sage: p.apply_simple_reflection_right(4) Type D affine permutation with window [1, -6, 11, 4]
>>> from sage.all import * >>> D = AffinePermutationGroup(['D',Integer(4),Integer(1)]) >>> p=D([Integer(1),-Integer(6),Integer(5),-Integer(2)]) >>> p.apply_simple_reflection_right(Integer(0)) Type D affine permutation with window [6, -1, 5, -2] >>> p.apply_simple_reflection_right(Integer(1)) Type D affine permutation with window [-6, 1, 5, -2] >>> p.apply_simple_reflection_right(Integer(4)) Type D affine permutation with window [1, -6, 11, 4]
- check()[source]#
Check that
self
is an affine permutation.EXAMPLES:
sage: D = AffinePermutationGroup(['D',4,1]) sage: p = D([1,-6,5,-2]) sage: p Type D affine permutation with window [1, -6, 5, -2]
>>> from sage.all import * >>> D = AffinePermutationGroup(['D',Integer(4),Integer(1)]) >>> p = D([Integer(1),-Integer(6),Integer(5),-Integer(2)]) >>> p Type D affine permutation with window [1, -6, 5, -2]
- has_left_descent(i)[source]#
Determine whether there is a descent at
i
.INPUT:
i
– an integer
EXAMPLES:
sage: D = AffinePermutationGroup(['D',4,1]) sage: p=D([1,-6,5,-2]) sage: [p.has_left_descent(i) for i in D.index_set()] [True, True, False, True, True]
>>> from sage.all import * >>> D = AffinePermutationGroup(['D',Integer(4),Integer(1)]) >>> p=D([Integer(1),-Integer(6),Integer(5),-Integer(2)]) >>> [p.has_left_descent(i) for i in D.index_set()] [True, True, False, True, True]
- has_right_descent(i)[source]#
Determine whether there is a descent at index
i
.INPUT:
i
– an integer
EXAMPLES:
sage: D = AffinePermutationGroup(['D',4,1]) sage: p=D([1,-6,5,-2]) sage: [p.has_right_descent(i) for i in D.index_set()] [True, True, False, True, False]
>>> from sage.all import * >>> D = AffinePermutationGroup(['D',Integer(4),Integer(1)]) >>> p=D([Integer(1),-Integer(6),Integer(5),-Integer(2)]) >>> [p.has_right_descent(i) for i in D.index_set()] [True, True, False, True, False]
- class sage.combinat.affine_permutation.AffinePermutationTypeG(parent, lst, check=True)[source]#
Bases:
AffinePermutation
- apply_simple_reflection_left(i)[source]#
Apply simple reflection indexed by \(i\) on values.
EXAMPLES:
sage: G = AffinePermutationGroup(['G',2,1]) sage: p=G([2, 10, -5, 12, -3, 5]) sage: p.apply_simple_reflection_left(0) Type G affine permutation with window [0, 10, -7, 14, -3, 7] sage: p.apply_simple_reflection_left(1) Type G affine permutation with window [1, 9, -4, 11, -2, 6] sage: p.apply_simple_reflection_left(2) Type G affine permutation with window [3, 11, -5, 12, -4, 4]
>>> from sage.all import * >>> G = AffinePermutationGroup(['G',Integer(2),Integer(1)]) >>> p=G([Integer(2), Integer(10), -Integer(5), Integer(12), -Integer(3), Integer(5)]) >>> p.apply_simple_reflection_left(Integer(0)) Type G affine permutation with window [0, 10, -7, 14, -3, 7] >>> p.apply_simple_reflection_left(Integer(1)) Type G affine permutation with window [1, 9, -4, 11, -2, 6] >>> p.apply_simple_reflection_left(Integer(2)) Type G affine permutation with window [3, 11, -5, 12, -4, 4]
- apply_simple_reflection_right(i)[source]#
Apply the simple reflection indexed by
i
on positions.EXAMPLES:
sage: G = AffinePermutationGroup(['G',2,1]) sage: p = G([2, 10, -5, 12, -3, 5]) sage: p.apply_simple_reflection_right(0) Type G affine permutation with window [-9, -1, -5, 12, 8, 16] sage: p.apply_simple_reflection_right(1) Type G affine permutation with window [10, 2, 12, -5, 5, -3] sage: p.apply_simple_reflection_right(2) Type G affine permutation with window [2, -5, 10, -3, 12, 5]
>>> from sage.all import * >>> G = AffinePermutationGroup(['G',Integer(2),Integer(1)]) >>> p = G([Integer(2), Integer(10), -Integer(5), Integer(12), -Integer(3), Integer(5)]) >>> p.apply_simple_reflection_right(Integer(0)) Type G affine permutation with window [-9, -1, -5, 12, 8, 16] >>> p.apply_simple_reflection_right(Integer(1)) Type G affine permutation with window [10, 2, 12, -5, 5, -3] >>> p.apply_simple_reflection_right(Integer(2)) Type G affine permutation with window [2, -5, 10, -3, 12, 5]
- check()[source]#
Check that
self
is an affine permutation.EXAMPLES:
sage: G = AffinePermutationGroup(['G',2,1]) sage: p = G([2, 10, -5, 12, -3, 5]) sage: p Type G affine permutation with window [2, 10, -5, 12, -3, 5]
>>> from sage.all import * >>> G = AffinePermutationGroup(['G',Integer(2),Integer(1)]) >>> p = G([Integer(2), Integer(10), -Integer(5), Integer(12), -Integer(3), Integer(5)]) >>> p Type G affine permutation with window [2, 10, -5, 12, -3, 5]
- has_left_descent(i)[source]#
Determines whether there is a descent at
i
.INPUT:
i
– an integer
EXAMPLES:
sage: G = AffinePermutationGroup(['G',2,1]) sage: p = G([2, 10, -5, 12, -3, 5]) sage: [p.has_left_descent(i) for i in G.index_set()] [False, True, False]
>>> from sage.all import * >>> G = AffinePermutationGroup(['G',Integer(2),Integer(1)]) >>> p = G([Integer(2), Integer(10), -Integer(5), Integer(12), -Integer(3), Integer(5)]) >>> [p.has_left_descent(i) for i in G.index_set()] [False, True, False]
- has_right_descent(i)[source]#
Determines whether there is a descent at index \(i\).
INPUT:
i
– an integer
EXAMPLES:
sage: G = AffinePermutationGroup(['G',2,1]) sage: p = G([2, 10, -5, 12, -3, 5]) sage: [p.has_right_descent(i) for i in G.index_set()] [False, False, True]
>>> from sage.all import * >>> G = AffinePermutationGroup(['G',Integer(2),Integer(1)]) >>> p = G([Integer(2), Integer(10), -Integer(5), Integer(12), -Integer(3), Integer(5)]) >>> [p.has_right_descent(i) for i in G.index_set()] [False, False, True]
- position(i)[source]#
Find the position
j
such theself.value(j) == i
.EXAMPLES:
sage: G = AffinePermutationGroup(['G',2,1]) sage: p = G([2, 10, -5, 12, -3, 5]) sage: [p.position(i) for i in p] [1, 2, 3, 4, 5, 6]
>>> from sage.all import * >>> G = AffinePermutationGroup(['G',Integer(2),Integer(1)]) >>> p = G([Integer(2), Integer(10), -Integer(5), Integer(12), -Integer(3), Integer(5)]) >>> [p.position(i) for i in p] [1, 2, 3, 4, 5, 6]
- to_type_a()[source]#
Return an embedding of
self
into the affine permutation group of type A.EXAMPLES:
sage: G = AffinePermutationGroup(['G',2,1]) sage: p = G([2, 10, -5, 12, -3, 5]) sage: p.to_type_a() Type A affine permutation with window [2, 10, -5, 12, -3, 5]
>>> from sage.all import * >>> G = AffinePermutationGroup(['G',Integer(2),Integer(1)]) >>> p = G([Integer(2), Integer(10), -Integer(5), Integer(12), -Integer(3), Integer(5)]) >>> p.to_type_a() Type A affine permutation with window [2, 10, -5, 12, -3, 5]
- value(i, base_window=False)[source]#
Return the image of the integer
i
under this permutation.INPUT:
base_window
– boolean indicating whetheri
is between 1 and \(k+1\); ifTrue
, will run a bit faster, but the method will screw up ifi
is not actually in the index set
EXAMPLES:
sage: G = AffinePermutationGroup(['G',2,1]) sage: p=G([2, 10, -5, 12, -3, 5]) sage: [p.value(i) for i in [1..12]] [2, 10, -5, 12, -3, 5, 8, 16, 1, 18, 3, 11]
>>> from sage.all import * >>> G = AffinePermutationGroup(['G',Integer(2),Integer(1)]) >>> p=G([Integer(2), Integer(10), -Integer(5), Integer(12), -Integer(3), Integer(5)]) >>> [p.value(i) for i in (ellipsis_range(Integer(1),Ellipsis,Integer(12)))] [2, 10, -5, 12, -3, 5, 8, 16, 1, 18, 3, 11]