Matroid database

Matroid 4.8.193

Label4.8.193
Idr4_n8_0********0****0*****0**0***********************00********************0
Rank4
n8

Basic invariants

Bases62
Circuits32
Flats70
Cyclic flats10
Loops0
Connected components1
Automorphisms8
Beta invariant12
Girth4
Simpleyes
Connectedyes
Uniformnot computed
Looplessyes
Colooplessyes
Pavingyes
Laminarno
Nestedno
Self dualyes
Identically self dualno
Series parallelno
Transversalno
Supersolvableno
Divisionally freeno
Orientableno
Three linesnot computed

Representability

Characteristic setnot realizable over any field []
Realizableno
Realizable char0no
Regularno
Binaryno
Ternaryno
Quaternaryyes
Graphicno

Realization space

Statuscomputed_realization_space
Dimension of realization space-1
Expected dimension over ℤnot computed
Components of realization space0
Free realization spaceno
Principal idealyes
Birational typeempty
how determined: birational type method: empty_char0
Birational type components
show
[]
Good basisnot computed
Good basis v21,3,5,6

Geometry

Realization space: scheme simple core idnot computed
Smooth char 0yes
Singular primes[]
Realization space: smooth over ℚnot computed
Realization space: smooth over ℤnot computed
Realization space: is regular schemenot computed
Realization space: singular fiber primesnot computed
Realization space: singular fiber characteristicsnot computed
Realization space: characteristic dimensionsnot computed
Realization space: characteristic dimension unexpectednot computed
Realization space: characteristic dimension variesnot computed

Other

Char poly splitsfalse
Simplicial arrangementno
Realization space: n qbar components0

Tutte polynomial

\(T = x_{0}^{4} + 4 x_{0}^{3} + 10 x_{0}^{2} + 8 x_{0} x_{1} + 12 x_{0} + x_{1}^{4} + 4 x_{1}^{3} + 10 x_{1}^{2} + 12 x_{1}\)

Realization space

Ring\(\mathbb{Z}[x_{1}, x_{2}]\)
Defining ideal\(\left(2\right)\)
Inequations\(x_{1} - 1 \neq 0\), \(x_{2} \neq 0\), \(x_{2} - 1 \neq 0\), \(x_{1} x_{2} - 2 x_{1} - 2 x_{2} + 2 \neq 0\), \(x_{1} + x_{2} - 1 \neq 0\), \(x_{1} \neq 0\), \(x_{2} - 2 \neq 0\), \(x_{1} - 2 \neq 0\)
Realization matrix\(\begin{pmatrix}1 & 1 & 0 & 0 & 0 & 0 & 1 & 1 \\ 0 & 0 & 1 & 1 & 0 & 0 & 1 & 1 \\ 0 & 1 & 0 & 1 & 1 & 0 & x_{1} & 1 \\ 0 & 1 & 0 & 1 & 0 & 1 & 0 & x_{2}\end{pmatrix}\)

Combinatorics

Computed on the fly from the id.

Bases (62){1,2,3,5} {1,2,4,5} {1,3,4,5} {2,3,4,5} {1,2,3,6} {1,2,4,6} {1,3,4,6} {2,3,4,6} {1,3,5,6} {2,3,5,6} {1,4,5,6} {2,4,5,6} {1,2,3,7} {1,2,4,7} {1,3,4,7} {2,3,4,7} {1,2,5,7} {2,3,5,7} {1,4,5,7} {3,4,5,7} {1,2,6,7} {1,3,6,7} {2,3,6,7} {1,4,6,7} {2,4,6,7} {3,4,6,7} {1,5,6,7} {2,5,6,7} {3,5,6,7} {4,5,6,7} {1,2,3,8} {1,2,4,8} {1,3,4,8} {2,3,4,8} {1,2,5,8} {1,3,5,8} {2,3,5,8} {1,4,5,8} {2,4,5,8} {3,4,5,8} {1,2,6,8} {1,3,6,8} {2,4,6,8} {3,4,6,8} {1,5,6,8} {2,5,6,8} {3,5,6,8} {4,5,6,8} {1,2,7,8} {1,3,7,8} {2,3,7,8} {1,4,7,8} {2,4,7,8} {3,4,7,8} {1,5,7,8} {2,5,7,8} {3,5,7,8} {4,5,7,8} {1,6,7,8} {2,6,7,8} {3,6,7,8} {4,6,7,8}
Non-bases (8){1,2,3,4} {1,2,5,6} {3,4,5,6} {1,3,5,7} {2,4,5,7} {2,3,6,8} {1,4,6,8} {5,6,7,8}
Circuits (32){1,2,3,4} {1,2,5,6} {3,4,5,6} {1,3,5,7} {2,4,5,7} {1,2,3,6,7} {1,2,4,6,7} {1,3,4,6,7} {2,3,4,6,7} {2,3,5,6,7} {1,4,5,6,7} {1,2,3,5,8} {1,2,4,5,8} {1,3,4,5,8} {2,3,4,5,8} {2,3,6,8} {1,4,6,8} {1,3,5,6,8} {2,4,5,6,8} {1,2,3,7,8} {1,2,4,7,8} {1,3,4,7,8} {2,3,4,7,8} {1,2,5,7,8} {2,3,5,7,8} {1,4,5,7,8} {3,4,5,7,8} {1,2,6,7,8} {1,3,6,7,8} {2,4,6,7,8} {3,4,6,7,8} {5,6,7,8}
Flats by rank (70)
Hyperplanes (32){1,2,3,4} {2,3,5} {1,4,5} {1,3,6} {2,4,6} {1,2,5,6} {3,4,5,6} {1,2,7} {2,3,7} {1,4,7} {3,4,7} {1,3,5,7} {2,4,5,7} {1,6,7} {2,6,7} {3,6,7} {4,6,7} {1,2,8} {1,3,8} {2,4,8} {3,4,8} {1,5,8} {2,5,8} {3,5,8} {4,5,8} {2,3,6,8} {1,4,6,8} {1,7,8} {2,7,8} {3,7,8} {4,7,8} {5,6,7,8}
Dual (rank 4)

Revlex encoding in this labeling (not canonicalized, so not linked): 0********************00***********************0**0*****0****0********0

Bases: {4,6,7,8} {3,6,7,8} {2,6,7,8} {1,6,7,8} {4,5,7,8} {3,5,7,8} {2,5,7,8} {1,5,7,8} {2,4,7,8} {1,4,7,8} {2,3,7,8} {1,3,7,8} {4,5,6,8} {3,5,6,8} {2,5,6,8} {1,5,6,8} {3,4,6,8} {1,4,6,8} {2,3,6,8} {1,2,6,8} {3,4,5,8} {2,4,5,8} {1,4,5,8} {2,3,5,8} {1,3,5,8} {1,2,5,8} {2,3,4,8} {1,3,4,8} {1,2,4,8} {1,2,3,8} {4,5,6,7} {3,5,6,7} {2,5,6,7} {1,5,6,7} {3,4,6,7} {2,4,6,7} {1,4,6,7} {2,3,6,7} {1,3,6,7} {1,2,6,7} {3,4,5,7} {2,4,5,7} {1,3,5,7} {1,2,5,7} {2,3,4,7} {1,3,4,7} {1,2,4,7} {1,2,3,7} {3,4,5,6} {2,4,5,6} {1,4,5,6} {2,3,5,6} {1,3,5,6} {1,2,5,6} {2,3,4,6} {1,3,4,6} {1,2,4,6} {1,2,3,6} {2,3,4,5} {1,3,4,5} {1,2,4,5} {1,2,3,5}

Loops: none. Parallel classes of size > 1: none.

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