Matroid database

Matroid 3.8.22

Label3.8.22
Idr3_n8_0******0******0**********0********0*******0****0**0*****
Rank3
n8
12345678

Affine diagram.

Basic invariants

Bases48
Circuits38
Flats22
Cyclic flats10
Loops0
Connected components1
Automorphisms48
Beta invariant7
Girth3
Simpleyes
Connectedyes
Uniformnot computed
Looplessyes
Colooplessyes
Pavingyes
Laminarno
Nestedno
Self dualno
Identically self dualno
Series parallelno
Transversalno
Supersolvableno
Divisionally freeno
Orientableno
Three linesyes

Representability

Characteristic setcharacteristic 0 and all primes [0]
Realizableyes
Realizable char0yes
Regularno
Binaryno
Ternaryyes
Quaternaryyes
Graphicno

Realization space

Statuscomputed_realization_space
Dimension of realization space0
Expected dimension over ℤ1
Components of realization space2
Free realization spaceno
Principal idealyes
Birational typepoint over Q(a)/(a^2 - a + 1)
how determined: birational type method: point_field
Birational type components
show
[
 {
  "dim": 0,
  "free_rank": 0,
  "torus_rank": 0,
  "core_dim": 0,
  "qbar_components": 2,
  "type": "point over Q(a)/(a^2 - a + 1)",
  "field": "Q(a)/(a^2 - a + 1)",
  "minpoly": "T^2 - T + 1",
  "degree": 2,
  "core_vars": [
   "x1"
  ],
  "core_gens": [
   "x1^2 - x1 + 1"
  ]
 }
]
Good basis1,2,4
Good basis v21,2,6

Geometry

Realization space: scheme simple core idr3_n8_0******0******0**********0********0*******0****0**0*****
Smooth char 0yes
Singular primes[3]
Realization space: smooth over ℚnot computed
Realization space: smooth over ℤno
how determined: smoothness method: certified_singular_fiber smoothness witness: 3
Realization space: is regular schemeyes
how determined: regularity method: direct_mixed_jacobian
Realization space: singular fiber primes[3]
how determined: singular fiber primes method: terminal_three_lines_integer_certificate
Realization space: singular fiber characteristicsnot computed
Realization space: characteristic dimensions
show
[
 {
  "p": 0,
  "d": 0
 }
]
how determined: characteristic dimensions method: cofinite_strong_groebner_candidates_exact
Realization space: characteristic dimension unexpectedno
Realization space: characteristic dimension variesno

Other

Char poly splitsfalse
Simplicial arrangementno
Realization space: n qbar components2

Tutte polynomial

\(T = x_{0}^{3} + 5 x_{0}^{2} + 8 x_{0} x_{1} + 7 x_{0} + x_{1}^{5} + 3 x_{1}^{4} + 6 x_{1}^{3} + 10 x_{1}^{2} + 7 x_{1}\)

Realization space

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

Combinatorics

Computed on the fly from the id.

Bases (48){1,2,4} {1,3,4} {2,3,4} {1,2,5} {1,3,5} {2,3,5} {2,4,5} {3,4,5} {1,2,6} {1,3,6} {2,3,6} {1,4,6} {3,4,6} {1,5,6} {2,5,6} {3,5,6} {4,5,6} {1,2,7} {1,3,7} {2,3,7} {1,4,7} {2,4,7} {1,5,7} {2,5,7} {3,5,7} {4,5,7} {1,6,7} {2,6,7} {3,6,7} {4,6,7} {1,2,8} {1,3,8} {2,3,8} {1,4,8} {2,4,8} {3,4,8} {1,5,8} {3,5,8} {4,5,8} {1,6,8} {2,6,8} {4,6,8} {5,6,8} {2,7,8} {3,7,8} {4,7,8} {5,7,8} {6,7,8}
Non-bases (8){1,2,3} {1,4,5} {2,4,6} {3,4,7} {5,6,7} {2,5,8} {3,6,8} {1,7,8}
Circuits (38){1,2,3} {1,4,5} {2,3,4,5} {2,4,6} {1,3,4,6} {1,2,5,6} {1,3,5,6} {2,3,5,6} {3,4,5,6} {1,2,4,7} {3,4,7} {1,2,5,7} {1,3,5,7} {2,3,5,7} {2,4,5,7} {1,2,6,7} {1,3,6,7} {2,3,6,7} {1,4,6,7} {5,6,7} {1,2,4,8} {1,3,4,8} {2,3,4,8} {2,5,8} {1,3,5,8} {3,4,5,8} {1,2,6,8} {3,6,8} {1,4,6,8} {1,5,6,8} {4,5,6,8} {1,7,8} {2,3,7,8} {2,4,7,8} {3,5,7,8} {4,5,7,8} {2,6,7,8} {4,6,7,8}
Flats by rank (22)
Hyperplanes (12){1,2,3} {3,5} {1,4,5} {1,6} {2,4,6} {2,7} {3,4,7} {5,6,7} {4,8} {2,5,8} {3,6,8} {1,7,8}
Lines (8){1,2,3} {1,4,5} {2,4,6} {3,4,7} {5,6,7} {2,5,8} {3,6,8} {1,7,8}
Dual (rank 5)

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

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

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

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