Matroid 3.7.7
| Label | 3.7.7 |
|---|---|
| Id | r3_n7_0******0******0*************0****** |
| Rank | 3 |
| n | 7 |
Basic invariants
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 | 2 |
| 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 | 1,2,4 |
| Good basis v2 | 1,2,5 |
Geometry
| Realization space: scheme simple core id | r3_n7_0******0******0*************0****** |
|---|---|
| Smooth char 0 | yes |
| Singular primes | [] |
| Realization space: smooth over ℚ | not computed |
| Realization space: smooth over ℤ | yes how determined: smoothness method: three_lines_deletion smoothness witness: 1=>r3_n6_0******************0 |
| Realization space: is regular scheme | yes how determined: regularity method: three_lines_deletion regularity witness: 1=>r3_n6_0******************0 |
| Realization space: singular fiber primes | [] how determined: singular fiber primes method: smooth_over_ZZ |
| Realization space: singular fiber characteristics | not computed |
| Realization space: characteristic dimensions | show[
{
"p": 0,
"d": 2
}
]how determined: characteristic dimensions method: cofinite_strong_groebner_candidates_exact |
| 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
\(T = x_{0}^{3} + 4 x_{0}^{2} + 4 x_{0} x_{1} + 6 x_{0} + x_{1}^{4} + 3 x_{1}^{3} + 6 x_{1}^{2} + 6 x_{1}\)
Realization space
| Ring | \(\mathbb{Z}[x_{1}, x_{2}]\) |
|---|---|
| Defining ideal | \(\left(0\right)\) |
| Inequations | \(x_{1} x_{2} - 1 \neq 0\), \(x_{2} - 1 \neq 0\), \(x_{2} \neq 0\), \(x_{1} - 1 \neq 0\), \(x_{1} \neq 0\) |
| Realization matrix | \(\begin{pmatrix}1 & 0 & 1 & 1 & 0 & 1 & 1 \\ 0 & 1 & 1 & 0 & 0 & x_{1} & 1 \\ 0 & 0 & 0 & 1 & 1 & 1 & x_{2}\end{pmatrix}\) |
Combinatorics
Computed on the fly from the id.
Bases (31)
{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} {3,4,7} {1,5,7} {2,5,7} {4,5,7} {1,6,7} {2,6,7} {3,6,7} {4,6,7} {5,6,7}Non-bases (4)
{1,2,3} {1,4,5} {2,4,6} {3,5,7}Circuits (23)
{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} {1,3,4,7} {2,3,4,7} {1,2,5,7} {3,5,7} {2,4,5,7} {1,2,6,7} {1,3,6,7} {2,3,6,7} {1,4,6,7} {3,4,6,7} {1,5,6,7} {2,5,6,7} {4,5,6,7}Flats by rank (22)
- rank 0 (1): {}
- rank 1 (7): {1} {2} {3} {4} {5} {6} {7}
- rank 2 (13): {1,2,3} {3,4} {2,5} {1,4,5} {1,6} {3,6} {2,4,6} {5,6} {1,7} {2,7} {4,7} {3,5,7} {6,7}
- rank 3 (1): {1,2,3,4,5,6,7}
Hyperplanes (13)
{1,2,3} {3,4} {2,5} {1,4,5} {1,6} {3,6} {2,4,6} {5,6} {1,7} {2,7} {4,7} {3,5,7} {6,7}Lines (4)
{1,2,3} {1,4,5} {2,4,6} {3,5,7}Dual (rank 4)
Revlex encoding in this labeling (not canonicalized, so not linked): ******0*************0******0******0
Bases: {3,5,6,7} {2,5,6,7} {1,5,6,7} {3,4,6,7} {2,4,6,7} {1,4,6,7} {1,3,6,7} {1,2,6,7} {3,4,5,7} {2,4,5,7} {1,4,5,7} {2,3,5,7} {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} {1,2,3,6} {2,3,4,5} {1,3,4,5} {1,2,4,5} {1,2,3,5} {1,2,3,4}
Loops: none. Parallel classes of size > 1: none.
Downloads
- Record as JSON
- OSCAR:
matroid_from_revlex_basis_encoding("0******0******0*************0******", 3, 7)