Obtaining a poset from a matrix

posets

asked 2023-04-30 16:11:07 +0200

klaaa
671 ●3 ●14 ●38

I have an upper triangular matrix M with entries only 0 or 1 where all diagonal entries are 1. I want to use Sage to test whether M is the lequal_matrix of a finite poset and to obtain that poset via Sage if this is the case. Is there an easy way to do this? I did not find anything i the poset manual that seems to work. Thanks for any help!

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answered 2023-04-30 21:55:02 +0200

FrédéricC

5123 ●3 ●43 ●111

Like this

sage: m = matrix(ZZ,2,2,[1,1,0,1])
sage: Poset(DiGraph(m-1, loops=False))
Finite poset containing 2 elements

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Perhaps this needs to be enclosed into try: ... except: ... to handle cases when matrix does not define a poset.

Max Alekseyev ( 2023-05-04 15:15:30 +0200 )edit

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Asked: 2023-04-30 16:11:07 +0200

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Last updated: Apr 30 '23

Obtaining a poset from a matrix edit