On 9/21/07, James wrote: > Is the behavior below legit? The code is just to illustrate > something for a class.
Jim, All you have to do to fix the code is replace lt(r)/lt(g) by lt(r)//lt(g) below. The expression lt(r)/lt(g) creates an element of Frac(R), so it is not iterable. Another option would be to replace lt(r)/lt(g) by R(lt(r)/lt(g)), which is slower, but safer in that if there were a bug and lt(g) doesn't divide lt(r) you'll get an error. In general f//g means "floor division in the same ring", so when g divides f you get back f/g as an element of R. -- William > > ----- > /Users/tmp/sage/poly1.py in div(f, g) > 30 def div(f,g): > 31 q,r = Integer(0),f > ---> 32 while not zero(r) and divides(lt(g),lt(r)): > 33 q = q + lt(r)/lt(g) > 34 r = r - (lt(r)/lt(g))*g > > /Users/tmp/sage/poly1.py in lt(f) > 9 > 10 def lt(f): > ---> 11 coeffs = list(f) > 12 d = len(coeffs) - Integer(1) > 13 return coeffs[d]*x**d > > <type 'exceptions.TypeError'>: 'FractionFieldElement' object is not > iterable > --------- > > > K = QQ > R.<x> = PolynomialRing(K) > f = 1 + 3*x + 7*x^5 > g = 1 + 2*x^2 > > def lt(f): > coeffs = list(f) > d = len(coeffs) - 1 > return coeffs[d]*x^d > > def deg(f): > return len(list(f)) - 1 > > def divides(f,g): > if deg(g) - deg(f) >= 0: > return True > else: > return False > > def zero(f): > if f == 0: > return True > else: > return False > > def div(f,g): > q,r = 0,f > while not zero(r) and divides(lt(g),lt(r)): > q = q + lt(r)/lt(g) > r = r - (lt(r)/lt(g))*g > print "hi" > return [q,r] > -- William Stein Associate Professor of Mathematics University of Washington http://wstein.org --~--~---------~--~----~------------~-------~--~----~ 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://sage.math.washington.edu/sage/ and http://sage.scipy.org/sage/ -~----------~----~----~----~------~----~------~--~---
