These clever hacks do not take away from Kevin's main points: that getting field automorphisms to act on objects like polynomials over the field, with related functionality (norms etc); and that basic functions related to polynomials (extracting coefficients and creating a poly from a list of coeffs) should not be hard to find in the documentation.
John On 9 April 2014 00:05, Nils Bruin <[email protected]> wrote: > On Tuesday, April 8, 2014 1:55:49 PM UTC-7, Nils Bruin wrote: >> >> F=Qxz(f) #this conveniently lifts z to a >> transcendental in Q[x,z] > > > Oops, that only works because of the last-resort attempt of converting f to > a string and then feeding the string to Qxz. One probably shouldn't rely on > such code in production situations. You'd be better off using > > F=Qxz({ (degx,degz) :cfz for degx,cfx in enumerate(f.list()) for degz,cfz in > enumerate(cfx.list())}) > > which won't win any prizes for legibility and only qualifies as a one-liner > in the technical sense, but it is much faster than the string-based > conversion. > > -- > You received this message because you are subscribed to the Google Groups > "sage-support" 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-support. > For more options, visit https://groups.google.com/d/optout. -- You received this message because you are subscribed to the Google Groups "sage-support" 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-support. For more options, visit https://groups.google.com/d/optout.
