Hi, and Welcome, On Mar 14, 2011, at 20:14 , Ben123 wrote:
> Hello. I'm a new user to Sage. I am trying to create a matrix without > knowing the values when it is initialized. All the examples I see have > static matrices like > A = matrix(QQ,2,2,[2,1,1,2]) > My goal is to create a 2x2 matrix which I can then give values for > later > A[1][1]=5 That is correct, although I am at a loss to explain why that's how it is. With your matrix, sage: A[1] (1, 2) so clearly, the rows are "tuples", which are immutable. Not all is lost, though: sage: A[1,1]=5 sage: A [2 1] [1 5] Perhaps someone with a closer understanding of the implementation can explain the details. HTH. Justin -- Justin C. Walker, Curmudgeon-At-Large Institute for the Enhancement of the Director's Income -------- When LuteFisk is outlawed, Only outlaws will have LuteFisk -------- -- 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 URL: http://www.sagemath.org
