{{{id=158| B = Matrix([[0,1],[-1,0]]) /// }}} {{{id=101| B /// \newcommand{\Bold}[1]{\mathbf{#1}}\left(\begin{array}{rr} 0 & 1 \\ -1 & 0 \end{array}\right) }}} {{{id=102| ClusterSeed? ///
File: /Users/sage/sage/local/lib/python2.6/site-packages/sage/combinat/cluster_algebra_quiver/cluster_seed.py
Type: <type ‘type’>
Definition: ClusterSeed( [noargspec] )
Docstring:
The cluster seed associated to an exchange matrix.
INPUT:
data – can be any of the following:
* QuiverMutationType * str - a string representing a QuiverMutationType * Quiver * Matrix - a skew-symmetrizable matrix * DiGraph - must be the input data for a quiver * List of edges - must be the edge list of a digraph for a quiverEXAMPLES:
sage: S = ClusterSeed(['A',5]); S A seed for a cluster algebra of rank 5 of type ['A', 5] sage: S = ClusterSeed(['A',[2,5],1]); S A seed for a cluster algebra of rank 7 of type ['A', [2, 5], 1] sage: T = ClusterSeed( S ); T A seed for a cluster algebra of rank 7 of type ['A', [2, 5], 1] sage: T = ClusterSeed( S._M ); T A seed for a cluster algebra of rank 7 sage: T = ClusterSeed( S.quiver()._digraph ); T A seed for a cluster algebra of rank 7 sage: T = ClusterSeed( S.quiver()._digraph.edges() ); T A seed for a cluster algebra of rank 7
File: /Users/sage/sage/local/lib/python2.6/site-packages/sage/combinat/cluster_algebra_quiver/quiver_mutation_type.py
Type: <class ‘sage.combinat.cluster_algebra_quiver.quiver_mutation_type.QuiverMutationTypeFactory’>
Definition: QuiverMutationType(*args)
Docstring:
Quiver mutation types can be seen as a slight generalization of generalized Cartan types.
Background on generalized Cartan types can be found at
http://en.wikipedia.org/wiki/Generalized_Cartan_matrix
For the compendium on the cluster algebra and quiver package in Sage see
http://arxiv.org/abs/1102.4844
A B-matrix is a skew-symmetrizable ( n x n )-matrix M. I.e., there exists an invertible diagonal matrix D such that DM is skew-symmetric. M can be encoded as a quiver by having a directed edge from vertex i to vertex j with label (a,b) if a = M_{i,j} > 0 and b = M_{j,i} < 0. We consider quivers up to mutation equivalence.
In particular, to a quiver mutation type we can associate a generalized Cartan type by sending M to the generalized Cartan matrix C(M) obtained by replacing all positive entries by their negatives and adding 2‘s on the main diagonal.
It appears that C(M) and C(M') are isomorphic Cartan types for mutation equivalent skew-symmetrizable matrices M and M'. Thus, all generalized Cartan types appear as well as quiver mutation types.
Constructs a quiver mutation type object. For the possible different types, please see the compendium. Kac’s classification types can also be used as input.
INPUT:
- letter, rank – letter is one of ‘A’,’B’,’C’,’D’,’E’,’F’,’G’ and rank is an integer
- letter, rank, twist – letter is one of ‘A’,’BB’,’CC’,’D’,’E’,’F’,’G’, ‘BC’, ‘BD’, ‘CD’, and rank is a tuple (b,c) or an integer and twist is an integer
- object – a quiver mutation type
EXAMPLES:
Finite types:
sage: QuiverMutationType('A',1)
['A', 1]
sage: QuiverMutationType('A',5)
['A', 5]
sage: QuiverMutationType('B',2)
['B', 2]
sage: QuiverMutationType('B',5)
['B', 5]
sage: QuiverMutationType('C',2)
['B', 2]
sage: QuiverMutationType('C',5)
['C', 5]
sage: QuiverMutationType('D',2)
[ ['A', 1], ['A', 1] ]
sage: QuiverMutationType('D',3)
['A', 3]
sage: QuiverMutationType('D',4)
['D', 4]
sage: QuiverMutationType('E',6)
['E', 6]
sage: QuiverMutationType('E',7)
['E', 7]
sage: QuiverMutationType('E',8)
['E', 8]
sage: QuiverMutationType('F',4)
['F', 4]
sage: QuiverMutationType('G',2)
['G', 2]
Affine types:
sage: QuiverMutationType('A',(1,1),1)
['A', [1, 1], 1]
sage: QuiverMutationType('A',(2,4),1)
['A', [2, 4], 1]
sage: QuiverMutationType('BB',1,1)
['A', [1, 1], 1]
sage: QuiverMutationType('BB',2,1)
['BB', 2, 1]
sage: QuiverMutationType('BB',4,1)
['BB', 4, 1]
sage: QuiverMutationType('CC',1,1)
['A', [1, 1], 1]
sage: QuiverMutationType('CC',2,1)
['CC', 2, 1]
sage: QuiverMutationType('CC',4,1)
['CC', 4, 1]
sage: QuiverMutationType('BC',1,1)
['BC', 1, 1]
sage: QuiverMutationType('BC',5,1)
['BC', 5, 1]
sage: QuiverMutationType('BD',3,1)
['BD', 3, 1]
sage: QuiverMutationType('BD',5,1)
['BD', 5, 1]
sage: QuiverMutationType('CD',3,1)
['CD', 3, 1]
sage: QuiverMutationType('CD',5,1)
['CD', 5, 1]
sage: QuiverMutationType('D',4,1)
['D', 4, 1]
sage: QuiverMutationType('D',6,1)
['D', 6, 1]
sage: QuiverMutationType('E',6,1)
['E', 6, 1]
sage: QuiverMutationType('E',7,1)
['E', 7, 1]
sage: QuiverMutationType('E',8,1)
['E', 8, 1]
sage: QuiverMutationType('F',4,1)
['F', 4, 1]
sage: QuiverMutationType('F',4,-1)
['F', 4, -1]
sage: QuiverMutationType('G',2,1)
['G', 2, 1]
sage: QuiverMutationType('G',2,-1)
['G', 2, -1]
Elliptic types:
sage: QuiverMutationType('E',6,[1,1])
['E', 6, [1, 1]]
sage: QuiverMutationType('E',7,[1,1])
['E', 7, [1, 1]]
sage: QuiverMutationType('E',8,[1,1])
['E', 8, [1, 1]]
Mutation finite types:
rank 2 cases:
sage: QuiverMutationType('R2',(1,1),2)
['A', 2]
sage: QuiverMutationType('R2',(1,2),2)
['B', 2]
sage: QuiverMutationType('R2',(1,3),2)
['G', 2]
sage: QuiverMutationType('R2',(1,4),2)
['BC', 1, 1]
sage: QuiverMutationType('R2',(1,5),2)
['R2', [1, 5], 2]
sage: QuiverMutationType('R2',(2,2),2)
['A', [1, 1], 1]
sage: QuiverMutationType('R2',(3,5),2)
['R2', [3, 5], 2]
exceptional quiver mutation types:
sage: QuiverMutationType('V',4,2)
['V', 4, 2]
sage: QuiverMutationType('W',4,2)
['W', 4, 2]
sage: QuiverMutationType('W',4,-2)
['W', 4, -2]
sage: QuiverMutationType('X',6,2)
['X', 6, 2]
sage: QuiverMutationType('Y',6,2)
['Y', 6, 2]
sage: QuiverMutationType('Z',6,2)
['Z', 6, 2]
sage: QuiverMutationType('Z',6,-2)
['Z', 6, -2]
Mutation infinite types:
infinite type E:
sage: QuiverMutationType('E',9,3)
['E', 8, 1]
sage: QuiverMutationType('E',10,3)
['E', 10, 3]
sage: QuiverMutationType('E',12,3)
['E', 12, 3]
sage: QuiverMutationType('AE',(1,1),3)
['AE', [1, 1], 3]
sage: QuiverMutationType('AE',(1,4),3)
['AE', [1, 4], 3]
sage: QuiverMutationType('BE',5,3)
['BE', 5, 3]
sage: QuiverMutationType('CE',5,3)
['CE', 5, 3]
sage: QuiverMutationType('DE',6,3)
['DE', 6, 3]
Grassmannian types:
sage: QuiverMutationType('GR',(2,4),3)
['A', 1]
sage: QuiverMutationType('GR',(2,6),3)
['A', 3]
sage: QuiverMutationType('GR',(3,6),3)
['D', 4]
sage: QuiverMutationType('GR',(3,7),3)
['E', 6]
sage: QuiverMutationType('GR',(3,8),3)
['E', 8]
sage: QuiverMutationType('GR',(3,10),3)
['GR', [3, 10], 3]
Triangular types:
sage: QuiverMutationType('TR',2,3)
['A', 3]
sage: QuiverMutationType('TR',3,3)
['D', 6]
sage: QuiverMutationType('TR',4,3)
['E', 8, [1, 1]]
sage: QuiverMutationType('TR',5,3)
['TR', 5, 3]
T types:
sage: QuiverMutationType('T',(1,1,1),3)
['A', 1]
sage: QuiverMutationType('T',(1,1,4),3)
['A', 4]
sage: QuiverMutationType('T',(1,4,4),3)
['A', 7]
sage: QuiverMutationType('T',(2,2,2),3)
['D', 4]
sage: QuiverMutationType('T',(2,2,4),3)
['D', 6]
sage: QuiverMutationType('T',(2,3,3),3)
['E', 6]
sage: QuiverMutationType('T',(2,3,4),3)
['E', 7]
sage: QuiverMutationType('T',(2,3,5),3)
['E', 8]
sage: QuiverMutationType('T',(2,3,6),3)
['E', 8, 1]
sage: QuiverMutationType('T',(2,3,7),3)
['E', 10, 3]
sage: QuiverMutationType('T',(3,3,3),3)
['E', 6, 1]
sage: QuiverMutationType('T',(3,3,4),3)
['T', [3, 3, 4], 3]
Reducible types:
sage: QuiverMutationType(['A',3],['B',4])
[ ['A', 3], ['B', 4] ]