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naiveChirotope -- compute the chirotope of a configuration via determinants in Macaulay2

Description

Computes the chirotope directly in Macaulay2 by enumerating all $d$-subsets of the columns and recording the sign of each $d \times d$ minor. Useful for verifying the topcom-based chirotope.

i1 : A = transpose matrix {{0,3},{0,1},{-1,-1},{1,-1},{-4,-2},{4,-2}}

o1 = | 0 0 -1 1  -4 4  |
     | 3 1 -1 -1 -2 -2 |

              2       6
o1 : Matrix ZZ  <-- ZZ
i2 : chirotope A == naiveChirotope A

o2 = true

Caveat

Slower than chirotope for configurations with many points.

See also

Ways to use naiveChirotope:

  • naiveChirotope(Matrix)

For the programmer

The object naiveChirotope is a method function with options.


The source of this document is in /build/reproducible-path/macaulay2-1.26.06+ds/M2/Macaulay2/packages/Triangulations.m2:2839:0.