I agree with you on the lambda part. I am still not sure with else
part because users may not right about whether the matrix is enough
sparse and the methods(which exploits sparsity) would be inefficient
if someone enters the dense matrix actually. Maybe we should have a
common matrix interface and it should be the job of module to
determine it's appropriate representation.
-Saurabh Jha
On Jun 4, 5:11 am, Chris Smith <smi...@gmail.com> wrote:
> Yes, the callable could create only a few non-zero entries. And only the
> non-zero entries are retained in the SparseMatrix so it is reasonable to
> keep that code:
>
> >>> SparseMatrix(3,3,lambda i,j: 1 if i==j else 0)
>
> [1, 0, 0]
> [0, 1, 0]
> [0, 0, 1]>>> _._smat
>
> {(0, 0): 1, (1, 1): 1, (2, 2): 1}
>
> Again, the "else" part allows dense input that has few entries to be stored
> in a compact way so there's no reason to disallow it AFAICT:
>
> >>> SparseMatrix([[0,0,1],[0,0,1]])
>
> [0, 0, 1]
> [0, 0, 1]>>> _._smat
>
> {(1, 2): 1, (0, 2): 1}
>
> >>> SparseMatrix(3,3,lambda i,j: 1 if i==j else 0)
>
> (The bugginess that Aaron refers to is perhaps refering to the former state
> of SparseMatrix; I think things are currently in pretty good shape.)
--
You received this message because you are subscribed to the Google Groups
"sympy" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to sympy+unsubscr...@googlegroups.com.
To post to this group, send email to sympy@googlegroups.com.
Visit this group at http://groups.google.com/group/sympy?hl=en-US.
For more options, visit https://groups.google.com/groups/opt_out.
