This is great, this is actually how I initially hoped it could be done. And yes - I am quite new to SAGE.
It's though still a bit messy, since when I in F2 request a random_element() I will only get "1" or "0". /David On Sep 29, 9:12 pm, "Justin C. Walker" <[EMAIL PROTECTED]> wrote: > On Sep 29, 2008, at 10:51 AM, David Møller Hansen wrote: > > > > > Thank you for you answer Justin and I should also apologize for my > > badly formulated question but you understood it correctly. > > > I just can't get SAGE to eat the line you write f=x^2+x+F1(1), it > > complains with: TypeError: unsupported operand parent(s) for '+': > > 'Symbolic Ring' and 'Finite Field in a of size 2^7' > > Any time you see 'Symbolic Ring', or something similar, in an error > message, you have run afoul of some short-cuts built into sage to > make things simple for those who are "new" to sage, or are just using > it as a quick and dirty calculator. > > The issue is that 'x' is predeclared as a symbolic calculus variable, > and you want it to be an indeterminate for use in a polynomial ring. > > My reply earlier finessed the problem by not mentioning that I > actually had this between defining F1 and defining f: > > sage: P1.<x>=PolynomialRing(F1) > > When you do this, your polynomial will actually be an element in F1 > [x], and not some strange symbolic thing that doesn't play well with > others :-} > > In short, the correct way to do what I showed earlier is > > sage: F1.<a> = GF(2^7) > sage: P1.<x>=PolynomialRing(F1) > sage: f=x^2+x+F1(1) > sage: F2=F1.extension(f,'u') > sage: F2 > Univariate Quotient Polynomial Ring in u over Finite Field in a of > size 2^7 with modulus u^2 + u + 1 > sage: a in F2 > True > > (which I just verified in a fresh run of sage 3.1.1). > > Sorry for the confusion. > > Justin > > -- > Justin C. Walker, Curmudgeon-At-Large > Director > Institute for the Enhancement of the Director's Income > -------- > Here lies Lester Moore > Two bullets from a .44 > No less, no more > -------- --~--~---------~--~----~------------~-------~--~----~ To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-support URLs: http://www.sagemath.org -~----------~----~----~----~------~----~------~--~---
