Hi Simon, > There are ways to create an empty matrix from scratch, whithout > calling zero_matrix first (namely by calling the matrix class).
Well, it's not very straight-forward, but I agree there is a way (which I didn't think of before) sage: from sage.matrix.matrix_mod2_dense import Matrix_mod2_dense sage: MS = MatrixSpace(GF(2),64000,64000) sage: A = Matrix_mod2_dense(MS,None,True,True) Btw. the speed argument does not seem to hold true for dense over GF(2): sage: MS = MatrixSpace(GF(2),10000,10000) sage: %timeit A = Matrix_mod2_dense(MS,None,True,True) 125 loops, best of 3: 2.25 ms per loop sage: %timeit _ = copy(A) 125 loops, best of 3: 6.37 ms per loop Which makes sense because we always return a zero matrix when we allocate in M4RI, so copy() is alloc + memcpy while just creating it is just an alloc. I guess one approach could be a class attribute which determines whether a cache should be used or not (i.e. by type). Another one would decide based on some dimension (I don't know which since that depends on the implementation heavily). Cheers, Martin -- name: Martin Albrecht _pgp: http://pgp.mit.edu:11371/pks/lookup?op=get&search=0x8EF0DC99 _otr: 47F43D1A 5D68C36F 468BAEBA 640E8856 D7951CCF _www: http://martinralbrecht.wordpress.com/ _jab: martinralbre...@jabber.ccc.de -- 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
