Hi Martin,
On 10 Jul., 20:38, Martin Albrecht
wrote:
> 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.
How does that work? I learnt the hard way: Allocating memory does not
necessarily mean
On Jul 10, 4:41 pm, Luca De Feo wrote:
> This is an easy one line change in sage.misc.misc. What do you think?
Sounds like a welcome improvement to me.
Rob
--
To post to this group, send an email to sage-devel@googlegroups.com
To unsubscribe from this group, send an email to
sage-devel+unsubs
Hi deprecation experts,
The current way to deprecate a function that has changed name is:
old_func = deprecated_function_alias(new_func, "Sage version")
which, upon calling old_func, takes care of printing a deprecation message
"(Since Sage version) old_func is deprecated. Plea
Hi Nils and Maarten,
Thanks for your comments.
> Excellent example. One can make even worse examples via submodules-of-
> submodules (which sage forgets about. So for a 2-dim subspace of a 3-
> dim subspace of a 4-dim subspace, you can't use length 2 sequences).
I wonder if the way the category
Thanks, Nils. I've added a link to this discussion on the Trac
ticket.
I agree that it might be nice if <= behaved like .is_submodule().
Rob
--
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...@googlegro
Hi Simon,
You have 100x100 matrices in both cases, the same as in my example.
No unfortunately I ended up making a mistake when I was moving code
between sage and my email client.
But what you do here is to use a different number of loops in the
"timeit" function -- you only make 100 runs,
Hi Robert,
On 10 Jul., 21:20, "Robert Goss" wrote:
> I had a go at this and found that for larger matrices it doesnt seem to
> hold (well for me at least)
>
> sage: from sage.matrix.matrix_modn_dense import Matrix_modn_dense
> sage: MS = MatrixSpace(GF(3),100,100)
> sage: M = Matrix_modn_dense(
PS:
I just got an alternative idea, that might be a little faster and more
flexible.
Let MS be a matrix space.
Note that it only (or at least mainly) depends on MS.__matrix_class
whether it is faster to copy or faster to create from scratch.
Hence, why not have a static method of MS.__matrix_cl
Simon,
But it DOES hold for dense matrices over GF(3):
sage: from sage.matrix.matrix_modn_dense import Matrix_modn_dense
sage: MS = MatrixSpace(GF(3),100,100)
sage: M = Matrix_modn_dense(MS, None,True,True)
sage: timeit("M = Matrix_modn_dense(MS, None,True,True)",
number=1)
1 loops, be
Hi Martin,
On 10 Jul., 20:38, Martin Albrecht
wrote:
> Btw. the speed argument does not seem to hold true for dense over GF(2):
>
> sage: MS = MatrixSpace(GF(2),1,1)
> sage: %timeit A = Matrix_mod2_dense(MS,None,True,True)
> 125 loops, best of 3: 2.25 ms per loop
> sage: %timeit _ = copy(
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
Hi Martin,
On 10 Jul., 16:21, Martin Albrecht
wrote:
> which means that whenever on calls matrix(K,m,n) for the first time, it
> creates two matrices which is a very very bad idea when working with big
> matrices (== RAM full)
I was searching the code of the "matrix" function, and the
"zero_matr
Hi there,
currently, MatrixSpace's zero_matrix command is implemented as follows:
@cached_method
def zero_matrix(self):
res = self.__matrix_class(self, 0, coerce=False, copy=False)
res.set_immutable()
return res
which means that whenever on calls matrix(K,m,n) for
I agree with nils his remark: "I would say Hom(W,W)(L) should be equivalent
to Hom(W,W)([W(l) for l in L])"
Currently however the output of Hom(W,W)(list of vectors) does not depend on
the ambiant space of the vectors in the list:
sage: H = QQ^3
sage: W = (H).subspace_with_basis([[0,1,0],[0,0,1
14 matches
Mail list logo
