Re: Pari query

[Alasdair McAndrew <amca01@gmail.com>]

Apparently factorff has been superseded by 
factormod, and you can see some examples with

gp > ?? factormod

For your problem, it seems that

gp > factormod(x^5+x^3+1, [t^5+t^2+1, 2])

is what you want.  To see this more easily:

gp > liftall(factormod(x^5+x^3+1, [t^5+t^2+1, 2]))

These examples are lifted almost verbatim from the examples given in the documentation.  

On Wednesday 10 November 2021 22:25:28 (+11:00), Harvey Rose wrote:

 

Dear Pari expert

      I am trying to use factorff(x,a,p) and I keep getting error messages.  For example I am wanting to factorise the polynomial t^5+t^3+1 modulo 2 over the finite field of order 32 generated by the polynomial t^5+t^2+1.  I am assuming that the field has basis 1 and a, say, and the non-zero elements of the field can be represented by the powers a^n for n between 1 and 31, or as a vector space of dim 5 with basis elements (1,a, a^2,a^3,a^4).

 

     When I try the factorff function I keep getting the error message : incorrect priority in factormod, variable x <=t. or something very similar.  I have tried using Mod(-,2) as coefficients of the polynomial x and/or polynomial p to no avail.  So when you have a spare bit of time I would welcome any help here.

 

Yours sincerely        Harvey Rose

Sent from Mail for Windows

 

-- 
0432 854 858
https://numbersandshapes.net