flipping (or, I guess, rotation) has already been fixed by kshyatt, who has been writing tests. (!)
https://github.com/JuliaLang/julia/pull/9593 I guess the flip is more of a mirror symmetry, but you should be able to copy her pull request to implement it. (Please do submit as a pull request.) The slicing thing also needs to be fixed, that would be good to open as an issue. --Tim On Wednesday, January 07, 2015 12:35:48 PM Stefan Karpinski wrote: > I suspect this is precisely the case. Please do open an issue. > > On Wed, Jan 7, 2015 at 12:24 PM, Kevin Squire <[email protected]> > > wrote: > > I would suggest doing a quick search on github for any issues related to > > sparse matrices, and if none are relevant, opening a new one. One likely > > possibility is that neither function has been specialized for sparse > > matrices, and that the general fallback version of these functions are > > slow > > for sparse matrices. In either case, a specialized function should be > > easy > > to code. > > > > Cheers, > > > > Kevin > > > > On Wed, Jan 7, 2015 at 9:20 AM, Christoph Ortner < > > > > [email protected]> wrote: > >> I don't have a solution, but a related comment: slicing of large sparse > >> matrices is very slow too. E.g., I like to assemble a stiffness matrix > >> (for > >> a PDE) with free boundary conditions and then impose clamped boundaries > >> by > >> taking a subset of the matrix, > >> > >> B = A[Ifree, Ifree] > >> > >> this is so slow that I had to completely give up on it and rewrite all my > >> assembly codes. > >> > >> I suspect that the flipxx functions and this are a similar issue? > >> > >> Is there already an issue filed for this? > >> > >> Christoph
