Karim Belabas on Thu, 14 Nov 2013 17:53:41 +0100


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Re: factorpadic() for non-squarefree polynomials


* Karim Belabas [2013-11-14 17:35]:
> * Bill Allombert [2013-11-14 14:33]:
> [...]
> > I do not know why it returns + O(3^0).
> 
> Because we define "reduction to precision p^r" in a silly way here
> (absolute instead of relative). The function quickly determines that the
> input is irreducible over Qp then insists on coercing the output to
> t_PADICs with absolute accuracy 3^5, thereby losing information.

Sorry, I misread what you wrote: with my explanation (which corresponds
to comments in the code, and I wrote both code and comments here), it should
return O(3^5), certainly not O(3^0)

=> there is a bug in Z_to_Zp().

Cheers,

    K.B.
--
Karim Belabas, IMB (UMR 5251)  Tel: (+33) (0)5 40 00 26 17
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