On Mon, Feb 15, 2010 at 10:59 AM, Robert Bradshaw <rober...@math.washington.edu> wrote: > On Feb 15, 2010, at 6:07 AM, Florent Hivert wrote: > >> Hi there, >> >> Isn't the following a bug ? >> >> sage: mat = matrix(ZZ, [[1,1],[1,1]], sparse=False) >> sage: type(mat) >> <type 'sage.matrix.matrix_integer_dense.Matrix_integer_dense'> >> sage: mat2 = matrix(ZZ, mat, sparse=True)
I didn't know you could even give a matrix as the input to the matrix constructor. If you type "matrix?" you'll see that of the many types of input that matrix takes, a matrix itself is definitely not one of them... however the docs specifically say: "Calling matrix() with a Sage object may return something that makes sense." That's what's happening here -- your matrix "mat" is just some sage object that has an "_matrix_" method. It's calling that method on mat. That method doesn't even take a sparse parameter. So technically the behavior you're seeing agrees with the stated documentation, so isn't a bug. However, I can see how it could be misleading! But fixing it could be a can of worms, so... thank you. -- William >> sage: type(mat2) >> <type 'sage.matrix.matrix_integer_dense.Matrix_integer_dense'> > > Looks like a bug to me. > > - Robert > > > -- > To post to this group, send an email to sage-devel@googlegroups.com > To unsubscribe from this group, send an email to > sage-devel+unsubscr...@googlegroups.com > For more options, visit this group at > http://groups.google.com/group/sage-devel > URL: http://www.sagemath.org > -- William Stein Associate Professor of Mathematics University of Washington http://wstein.org -- To post to this group, send an email to sage-devel@googlegroups.com To unsubscribe from this group, send an email to sage-devel+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URL: http://www.sagemath.org
