On Dec 29, 2008, at 4:53 PM, Robert Bradshaw wrote: > > On Dec 29, 2008, at 1:38 PM, Justin Walker wrote: > >> On Dec 29, 2008, at 3:32 PM, Santanu Sarkar wrote: >> >>> I write a program in SAGE as follows: >>> R.<x1,x2>=QQ[] >>> M=matrix(R,1,2,[x1+x2,x1*x2]) >>> may i do following steps to extract polynomials from matrix? >>> 1) x = list(M) >>> 2) f1 = x[0] >>> 3) f2 = x[1] >>> is f1 & f2 are polynomials? >>> if not how i can get them? please help me! >> >> I think that >> >> sage: x = M.list() >> >> will do what you want. >> >> I'm not sure why list(M) doesn't do "the right thing": >> >> sage: list(M) >> [(x1 + x2, x1*x2)] > > list(M) gives a list of rows, not entries. > > sage: R.<x1,x2>=QQ[] > sage: M=matrix(R,1,2,[x1+x2,x1*x2]) > sage: M[0] > (x1 + x2, x1*x2) > sage: parent(M[0]) > Ambient free module of rank 2 over the integral domain Multivariate > Polynomial Ring in x1, x2 over Rational Field > sage: list(M)[0] > (x1 + x2, x1*x2) > > Same with indexing with using one index. Since matrices are two- > dimensional, this seems to be the "right thing" for me.
Hmm...I see what you mean... sage: N=matrix(R,2,1,[x1+x2,x1*x2]) sage: N [x1 + x2] [ x1*x2] sage: y=list(N) sage: y [(x1 + x2), (x1*x2)] Curiouser and curiouser... I guess one man's "object" is another man's ... Is there some reason that "rows" trump "columns"? Is this an artifact of implementation, e.g., a matrix is a list of rows? Should "list(obj)" do "obj.list()"? I'm more curious than complaining; seems a bit counterintuitive to me. Justin -- Justin C. Walker, Curmudgeon at Large Institute for the Absorption of Federal Funds ----------- Like the ski resort full of girls hunting for husbands and husbands hunting for girls, the situation is not as symmetrical as it might seem. - Alan MacKay -- --~--~---------~--~----~------------~-------~--~----~ To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to sage-support-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-support URLs: http://www.sagemath.org -~----------~----~----~----~------~----~------~--~---
