On Mon, Feb 15, 2010 at 1:35 PM, Florent Hivert <florent.hiv...@univ-rouen.fr> wrote: > Hi William, > >> >> 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. > > My American language is not very good... I'm not sure what you mean by "could > be a can of worms, so... thank you".
Sorry, that was too idiomatic. Probably even Americans wouldn't understand. I meant: (1) fixing this right might be surprisingly hard -- it's one of those issues that one starts working on thinking it will take "5 minutes", but it takes longer than 5 minutes. (2) I think it would be wonderful if you do fix it, and I'll greatly appreciate it. > Anyway, I'm ok fixing it if it is not too > complicated. Specifically, I'm ready to put a patch which calls the > constructor of MatrixSpace as in > sage: mat = matrix(ZZ, [[1,1],[1,1]], sparse=False) > sage: type(mat) > <type 'sage.matrix.matrix_integer_dense.Matrix_integer_dense'> > sage: res = MatrixSpace(ZZ, 2, 2, sparse=True)(mat) > sage: type(res) > <type 'sage.matrix.matrix_integer_sparse.Matrix_integer_sparse'> > Is it ok ? > Yes. However, please change the docstring for matrix to also say what happens when a matrix is passed in. Currently the docstring says (indirectly) that _matrix_ will get called, but you'll change that, for the better. william -- 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
