a bug in charpoly

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lukamar
Messages : 331
Inscription : ven. juin 30, 2017 9:55 am
Localisation : Zagreb, Croatia

a bug in charpoly

Message par lukamar » lun. mai 28, 2018 6:11 am

There is apparently some bug in the command charpoly. If I enter

Code : Tout sélectionner

A:=[[0,1,0,1,1,1,0,0,0,0,0,0,1,0,0,1],[1,0,1,0,0,1,1,0,0,0,0,0,1,1,0,0],[0,1,0,1,0,0,1,1,0,0,0,0,0,1,1,0],[1,0,1,0,1,0,0,1,0,0,0,0,0,0,1,1],[1,0,0,1,0,1,0,1,1,1,0,0,0,0,0,0],[1,1,0,0,1,0,1,0,0,1,1,0,0,0,0,0],[0,1,1,0,0,1,0,1,0,0,1,1,0,0,0,0],[0,0,1,1,1,0,1,0,1,0,0,1,0,0,0,0],[0,0,0,0,1,0,0,1,0,1,0,1,1,1,0,0],[0,0,0,0,1,1,0,0,1,0,1,0,0,1,1,0],[0,0,0,0,0,1,1,0,0,1,0,1,0,0,1,1],[0,0,0,0,0,0,1,1,1,0,1,0,1,0,0,1],[1,1,0,0,0,0,0,0,1,0,0,1,0,1,0,1],[0,1,1,0,0,0,0,0,1,1,0,0,1,0,1,0],[0,0,1,1,0,0,0,0,0,1,1,0,0,1,0,1],[1,0,0,1,0,0,0,0,0,0,1,1,1,0,1,0]];
charpoly(A,x)
I get "Not invertible Error". However, the command

Code : Tout sélectionner

det(x*idn(16)-A)
gives the expected result.

parisse
Messages : 5734
Inscription : mar. déc. 20, 2005 4:02 pm
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Re:

Message par parisse » lun. mai 28, 2018 4:26 pm

Indeed, missing % modulo at line 12742 in vecteur.cc.

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