On 12/5/12 7:46 AM, John Cremona wrote:
I don't know why this takes so long:I have a field F (a snumber field of high degree, 288 in fact) and want to create a 100x100 matrix over F from a list of 100 lists of 100 elements of F, while I will call "entries". If I do M = Matrix(entries) which certainly works fine with smaller examples, then I get tired of waiting (after 10 or 15 minutes) and cannot even interrupt with Ctrl-C. But if I do M = copy(MatrixSpace(F,100).zero_matrix()) for i in range(100): for j in range(100): M[i,j] = entries[i,j] it works in a few seconds. So what is going wrong with the first (simpler) way?
If you just do Matrix(entries), it tries to guess the right base ring (using the Sequence() command, IIRC). In the second example, you are explicitly telling Sage the base ring. I wonder if that is what is going on. To check, can you try doing:
matrix(F, entries) Thanks, Jason -- You received this message because you are subscribed to the Google Groups "sage-support" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. Visit this group at http://groups.google.com/group/sage-support?hl=en.
