# thetaMatroid -- theta matroid

## Synopsis

• Usage:
M = thetaMatroid n
• Inputs:
• Outputs:
• , the theta matroid

## Description

The family of theta matroids appears in Oxley, p. 663. For a given n, thetaMatroid n has 2n elements and rank n.

A notable feature of this family is that thetaMatroid n is representable over a field iff the field has at least n - 1 elements (a property also shared by uniformMatroid(2, n)).

 i1 : M = thetaMatroid 3 o1 = a "matroid" of rank 3 on 6 elements o1 : Matroid i2 : areIsomorphic(M, matroid completeGraph 4) o2 = true