The problem is that this issue also occurs for R.<x>=Qp(5)[] f=x^2 f.factor(), I was trying to fiddle with it and accidently copied the wrong code
On Tuesday, April 28, 2015 at 1:38:49 PM UTC-4, Nils Bruin wrote: > > On Tuesday, April 28, 2015 at 10:28:06 AM UTC-7, Joao Alberto de Faria > wrote: >> >> What is the difficulty in factoring polynomials with multiple roots over >> the p-adic ring? >> >> [[[ R.<x>=Qp(5)[] >> f=x^2 >> g=gcd(f,f.derivative()) >> (f/g).factor() ]]] >> >> returns the following error: >> >> sage.rings.padics.precision_error.PrecisionError: p-adic factorization >> not well-defined since the discriminant is zero up to the requestion >> p-adic precision >> >> > You didn't do what you think you did there: > > sage: f/g > ((1 + O(5^20))*x^2)/((1 + O(5^20))*x) > > It looks like sage is being conservative here in taking out apparent > common factors. Calling "factor" on that will probably attempt to factor > numerator and denominator separately. You'd really want to do a long > division here: > > sage: f // g > (1 + O(5^20))*x > sage: (f//g).factor() > (1 + O(5^20))*x + (O(5^20)) > > Checking the remainder: > > sage: f % g > (O(5^20))*x^2 > > so it's indeed indistinguishable from 0. > -- You received this message because you are subscribed to the Google Groups "sage-devel" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/sage-devel. For more options, visit https://groups.google.com/d/optout.
