Thank you Simon, I will try that. For those who are looking to reproduce my problem, the code is very very simple:
load SPOCs.sage save (SPOC,'SPOCs.sobj') SPOCs.sage, approx 12MB, defines SPOC as a list of matrices. It is available at http://www.math.utexas.edu/~allcock/SPOCs.sage Thanks folks, Daniel On Nov 3, 2:16 am, Simon King <[EMAIL PROTECTED]> wrote: > Dear Daniel, > > On Nov 2, 5:12 pm, Daniel Allcock <[EMAIL PROTECTED]> wrote: > > > Hi all, just got started with SAGE and I hope someone has a suggestion > > for me. I have a .sage file defining a big list of approx 170,000 4x4 > > matrices with rational number entries, which I will want SAGE to do > > various things to. It takes SAGE 4-5 minutes to read in the file > > (which was produced by a C++ program), and surely this can be > > improved. > > Of course, without seeing the code I have no clear idea why this takes > so long and blows up the memory. But one remark: There are different > ways to create a matrix over QQ, and they do not all take the same > time. > Examples: > sage: timeit('M=Matrix([[1/2,2/3],[3/4,4/5]])') > 625 loops, best of 3: 212 µs per loop > > sage: timeit('M=Matrix(QQ, > 2,2);M[0,0]=1/2;M[0,1]=2/3;M[1,0]=3/4;M[1,1]=4/5') > 625 loops, best of 3: 111 µs per loop > > sage: MS=MatrixSpace(QQ,2,2) > sage: timeit('M=MS(1/2,2/3,3/4,4/5)') > 625 loops, best of 3: 70.4 µs per loop > > Cheers > Simon --~--~---------~--~----~------------~-------~--~----~ 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 -~----------~----~----~----~------~----~------~--~---
