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swirl -- swirl matroid

Description

The family of swirls appears in Oxley, p. 664. The rank-r free swirl has 2r elements and rank r.

i1 : areIsomorphic(swirl 3, uniformMatroid_3 6)

o1 = true
 
i2 : M = swirl 4

o2 = a "matroid" of rank 4 on 8 elements

o2 : Matroid
 
i3 : betti ideal M

            0  1
o3 = total: 1 44
         0: 1  .
         1: .  .
         2: .  .
         3: .  4
         4: . 40

o3 : BettiTally
 
i4 : M == dual M

o4 = true
 
i5 : getSeparation(M, 3)

o5 = set {0, 1, 6, 7}

o5 : Set

See also

Ways to use swirl:

  • swirl(ZZ)

For the programmer

The object swirl is a method function.

The source of this document is in Matroids/doc-Matroids.m2:3284:0.