Matroid 3.7.40

Label	3.7.40
Id	`r3_n7_00000000000000000**`
Rank	3
n	7

Affine diagram (real realization). Loops (not drawn): 1.

Basic invariants

Bases	18
Circuits	12
Flats	19
Cyclic flats	4
Loops	1
Connected components	2
Automorphisms	8
Beta invariant	0
Girth	1
Simple	no
Connected	no
Uniform	not computed
Loopless	no
Coloopless	yes
Paving	no
Laminar	no
Nested	no
Self dual	no
Identically self dual	no
Series parallel	no
Transversal	yes
Supersolvable	no
Divisionally free	no
Orientable	yes
Three lines	unknown

Representability

Characteristic set	characteristic 0 and all primes `[0]`
Realizable	yes
Realizable char0	yes
Regular	no
Binary	no
Ternary	no
Quaternary	yes
Graphic	no

Realization space

Status	computed_realization_space
Dimension of realization space	0
Expected dimension over ℤ	3
Components of realization space	1
Free realization space	yes
Principal ideal	yes
Birational type	rational how determined: birational type method: `free_presentation`
Birational type components	show [ { "dim": 2, "free_rank": 2, "torus_rank": 2, "core_dim": 0, "qbar_components": 1, "type": "rational", "reason": "free realization space" } ]
Good basis	unknown
Good basis v2	2,3,5

Geometry

Realization space: scheme simple core id	`r3_n6_0****0**********`
Smooth char 0	unknown
Singular primes	unknown
Realization space: smooth over ℚ	not computed
Realization space: smooth over ℤ	yes how determined: smoothness method: `simple_core` smoothness witness: `r3_n6_0****0**********`
Realization space: is regular scheme	yes how determined: regularity method: `simple_core` regularity witness: `r3_n6_0****0**********`
Realization space: singular fiber primes	[] how determined: singular fiber primes method: `simple_core`
Realization space: singular fiber characteristics	not computed
Realization space: characteristic dimensions	show [ { "p": 0, "d": 2 } ] how determined: characteristic dimensions method: `simple_core`
Realization space: characteristic dimension unexpected	no
Realization space: characteristic dimension varies	no

Other

Char poly splits	false
Simplicial arrangement	no
Realization space: n qbar components	1

Tutte polynomial

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

Realization space

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

Combinatorics

Computed on the fly from the id.

Bases (18)

{2,3,5} {2,4,5} {3,4,5} {2,3,6} {2,4,6} {3,4,6} {3,5,6} {4,5,6} {2,3,7} {2,4,7} {3,4,7} {2,5,7} {3,5,7} {4,5,7} {2,6,7} {3,6,7} {4,6,7} {5,6,7}

Non-bases (17)

{1,2,3} {1,2,4} {1,3,4} {2,3,4} {1,2,5} {1,3,5} {1,4,5} {1,2,6} {1,3,6} {1,4,6} {1,5,6} {2,5,6} {1,2,7} {1,3,7} {1,4,7} {1,5,7} {1,6,7}

Circuits (12)

{1} {2,3,4} {2,5,6} {3,4,5,6} {2,3,5,7} {2,4,5,7} {3,4,5,7} {2,3,6,7} {2,4,6,7} {3,4,6,7} {3,5,6,7} {4,5,6,7}

Flats by rank (19)

rank 0 (1): {1}
rank 1 (6): {1,2} {1,3} {1,4} {1,5} {1,6} {1,7}
rank 2 (11): {1,2,3,4} {1,3,5} {1,4,5} {1,3,6} {1,4,6} {1,2,5,6} {1,2,7} {1,3,7} {1,4,7} {1,5,7} {1,6,7}
rank 3 (1): {1,2,3,4,5,6,7}

Hyperplanes (11)

{1,2,3,4} {1,3,5} {1,4,5} {1,3,6} {1,4,6} {1,2,5,6} {1,2,7} {1,3,7} {1,4,7} {1,5,7} {1,6,7}

Lines (2)

{1,2,3,4} {1,2,5,6}

Dual (rank 4)

Revlex encoding in this labeling (not canonicalized, so not linked): ****0***0**0*00**00**0*00**0*000000

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

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

Downloads

Record as JSON
OSCAR: matroid_from_revlex_basis_encoding("000000*0**00*0**00**00*0**0***0****", 3, 7)