Hi, the second solution is indeed very nice. I tested with A = Matrix(QQ, 2,3, [1,2,3,4,5,6]);A giving: [1 2 3] [4 5 6] res=[A[rows,cols] for cols in Combinations(A.ncols(),2) for rows in Combinations(A.nrows(),2)];res
[[1 2] [4 5], [1 3] [4 6], [2 3] [5 6]] this is more or less my question this output is not really readable though correct. for i in range(len(res)):print res[i].det() -3 -6 -3 A.minors(2) [-3, -6, -3] And some different, how do Ishow output easier, is HERE a possibility to show a picture (screen capture) of sage-sheet? Greets Peter 2010/2/2 Jason Grout <jason-s...@creativetrax.com> > On 02/01/2010 08:12 AM, javier wrote: > >> You can see the source of the "minors" method using >> >> sage: M.minors?? >> >> (you need to have defined M beforehand). >> >> By browsing at that source one can easily find the general way of >> doing it: >> >> sage: A = Matrix(QQ, 3, [1,2,3,4,5,6,7,8,9]) >> sage: [A.matrix_from_rows_and_columns(rows, cols) for cols in >> combinations_iterator(range(A.ncols()), 2) for rows in >> combinations_iterator(range(A.nrows()),2)] >> [ >> [1 2] [1 2] [4 5] [1 3] [1 3] [4 6] [2 3] [2 3] [5 6] >> [4 5], [7 8], [7 8], [4 6], [7 9], [7 9], [5 6], [8 9], [8 9] >> ] >> >> > > Or slightly easier to read: > > > sage: A = Matrix(QQ, 3, [1,2,3,4,5,6,7,8,9]) > sage: [A[rows,cols] for cols in Combinations(A.ncols(),2) for rows in > Combinations(A.nrows(),2)] > > [ > [1 2] [1 2] [4 5] [1 3] [1 3] [4 6] [2 3] [2 3] [5 6] > [4 5], [7 8], [7 8], [4 6], [7 9], [7 9], [5 6], [8 9], [8 9] > ] > > > > Thanks, > > Jason > > -- > Jason Grout > > > -- > 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<sage-support%2bunsubscr...@googlegroups.com> > For more options, visit this group at > http://groups.google.com/group/sage-support > URL: http://www.sagemath.org > -- 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
